bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum composition of the coelacanth, Latimeria chalumnae Smith
Authors: Griffith Robert W. , Umminger Bruce L. , Grant Blake F. , Pang Peter K. T. , Pickford Grace E. 
Published: June 2005

AbstractInorganic and organic constituents were studied on blood serum collected from a living specimen of the coelacanth, Latimeria chalumnae. Inorganic electrolytes determined included sodium (196.7 mM/l), potassium (5.78 mM/l), magnesium (5.30 mM/l), calcium (4.94 mM/l), chloride (186.7 mM/l), bicarbonate (9.60 mM/l), phosphate (5.08 mM/l), and sulfate (4.80 mM/l). Serum urea (377 mM/l) and trimethylamine oxide (122 mM/l) were high as previously reported, and accounted for the bulk of the total non‐protein nitrogen (1199 mg%); total amino acids added a small but not insignificant fraction (21.9 mg%). High serum lactate (16.5 mM/l) and glucose (6.57 mM/l) levels were probably indicative of stress; glucose was the only carbohydrate present in appreciable amounts in the serum, although traces of glucuronic acid and rhamnose were found. Serum total cholesterol was 3.91 mM/l, organically bound phosphorus 1.99 mM/l and total proteins 2.84 g%. Three major protein fractions were evident from cellulose acetate electrophoresis and at least 11 peaks were demonstrable by acrylamide gel electrophoresis. Latimeria serum lacks a protein component with a mobility approaching that of human serum albumin. Serum osmolarity (932 mOsm/l) was somewhat lower than that of sea water collected at the site of capture of the specimen (1035 mOsm/l). Evolutionary implications of the similarity of Latimeria serum chemistry to that of other marine fishes are discussed.
Ultrastructural effects of dark‐adaptation on eyes of a snail. Helix aspersa
Authors: Eakin Richard M. , Brandenburger Jean L. 
Published: June 2005

AbstractPulmonate snails (Helix aspersa) were raised from embryos to adulthood in total darkness. Unique ultrastructural features found in their photosensory cells were: 1. Break up of large aggregations of 800 A photic vesicles into smaller clusters by thick layers of membranes. 2. Increase in lipid droplets and in number and size of lysosomes. 3. Decrease in formation of photic vesicles by Golgi centers. 4. Flattening and bending of the tips of the microvilli. Tentative conclusions: the reduction in number of photic vesicles in dark‐adapted snails, by break down and decreased production, supports the hypothesis that the vesicles transport materials (photopigment ?) essential for light‐sensitivity of the microvilli.
In vitro effects of prolactin and cortisol on water permeability of the urinary bladder of the teleost Gillichthys mirabilis
Authors: Doneen Byron A. , Bern Howard A. 
Published: June 2005

AbstractUrinary bladders of the euryhaline teleost Gillichthys mirabilis were maintained in organ culture under defined conditions for four days. Examination of bladders cultured in medium containing cortisol or prolactin or both hormones indicates that cortisol increases bladder water permeability and that prolactin antagonizes the cortisol effect, causing a reduction in water permeability. Bladders co‐cultured with teleost pituitaries or with teleost rostral pars distalis is show a pronounced reduction in osmotic permeability. The effects of prolactin and cortisol in vivo appear to be reproducible in vitro.
Functional volume of frog eggs: Equivalence of metabolite diffusion space in chemically demembranated embryos and aqueous phase (non‐yolk) volume
Authors: Melton C. G. , Smorul R. P. 
Published: June 2005

AbstractVitelline membranes were removed from two‐cell Rana pipiens embryos by papain‐cysteine. Uptake of several different metabolites was enhanced, some more than others, but they all slowly reached about the same plateau, 11.2–13% (average) volumetric equilibration of the embryos with the radioactive medium. Active transport was ruled out as the uptake mechanism.Similarly, direct measurement of the volume of the aqueous phase, or “non‐yolk” cytoplasm, of egg homogenates gave an average value of 12.3% of the total egg volume. We conclude that this represents the available embryonic diffusion space and that the metabolites saturated it by passive diffusion. The importance of the concept of non‐yolk cytoplasm, or egg functional volume, as a developmentally significant parameter is discussed.
Further evidence for a developmental change in morphogenetic properties of embryonic chick heart cells
Authors: Lesseps Roland J. , Brown Shelia A. 
Published: June 2005

AbstractRecent experiments involving the reaggregation of dissociated cells and fusion of intact tissue fragments have indicated that whereas heart cells and tissue fragments from young chick embryos (1.5–2 days) displayed a tendency to assume external positions in combination with neural tube, those from older embryos (4–5 days) tended to segregate to the inside of neural tube. In the present experiments, we have used the same techniques in conjunction with autoradiography to determine the relative positions of two‐day and five‐day heart ventricle cells in fusion masses and in reaggregates. Sections of 30 fusion masses revealed that the two‐day heart fragment enveloped the five‐day heart fragment in every case. Sections of 29 reaggregates showed that the two‐day and five‐day heart cells were still randomly mixed at the end of the two and one‐half day culture period. The consistent spreading of intact two‐day heart ventricle fragments over five‐day heart ventricle fragments confirms the indication of the previous experiments that heart cells change their morphogenetic properties between two days and five days of incubation. The failure of five‐day and two‐day heart cells to sort out from one another could be due to a decreased cohesiveness of five‐day heart cells caused by the trypsin dissociation procedure.
Effect of experimentally induced anemia on the testicular activity of the toad (Bufo melanostictus)
Authors: Boral M. C. , Kaul Pratibha , Dey Sudhansu K. , Deb C. 
Published: June 2005

AbstractAnemia induced experimentally either by administration of phenylhydrazine or by splenectomy stimulated spermatogenic and steroidogenic activities in the testes of the toad (Bufo melanostictus). It is concluded that the stimulated activity of the testes is mediated through the hypothalamo‐pituitary axis.
The occurrence and possible functional significance of ‐S‐S‐ crosslinks in sperm heads, with particular reference to eutherian mammals
Authors: Bedford J. M. , Calvin H. I. 
Published: June 2005

AbstractThe extraordinary resistance to disruption shown by the eutherian sperm nucleus is associated with a significant complement of ‐S‐S‐ crosslinks within the chromatin. The present light and electron microscopic study, in which the spermatozoa of many vertebrates and some invertebrates were exposed to SDS with or without dithiothreitol, demonstrates that the extreme degree of disulfide bonding in the sperm chromatin of eutherian mammals is highly unusual in a comparative sense. In no other species did the sperm nucleus display a resistance to disruption comparable to that in eutherians; on the contrary, in most groups including prototherian and metatherian mammals, such crosslinks are absent or relatively sparse, the greatest degree of crosslinking outside the eutheria being seen in octopus and skate.The suggestion is advanced that the unusually thiol‐rich protamines have evolved as a structural adaptation which, through crosslinking, endows the sperm head with a rigidity of possible importance in the penetration phase of fertilization. This seems likely because (1) any degree of ‐S‐S‐ determined stability present or inducible in sperm chromatin often appears more intense in or is confined to the anterior region of the nucleus (e.g., newt, snail, turtle and immature eutherian spermatozoa); (2) the zona pellucida, which the fertilizing sperm must penetrate, is an unusually thick, compact and resilient coat in the eutherian ovum in particular; and (3) the occasional observation of a sperm nucleus buckled within the pathway of its penetration into the rabbit zona pellucida suggests that in eutheria this tough vestment presents a relatively rigid barrier to the sperm head.Its apical location suggests a similar structural role for the ‐S‐S‐ stabilised perinuclear projection, or “perforatorium” around the leading border of the sperm nucleus in eutherians as well as in some non‐eutherian species, such as octopus, snake and turtle.
Spermatozoan vesicle loss during penetration of the female gonangium in the hydroid. Campanularia flexuosa
Authors: O'Rand Michael G. , Miller Richard L. 
Published: June 2005

AbstractFertilization in the hydrozoan Campanularia flexuosa is internal and may be considered to include events in the female reproductive organ (the gonangium) prior to zygote formation. Prior to fertilization the spermatozoan must move through the female gonangium to the site of sperm‐egg fusion. The female gonangium contains sheets of epithelial cells which distally line the entrance and proximally form passageways that lead to and surround the eggs. After chemotactic attraction to the gonangium aperture, the spermatozoa adhere to the epithelial cells by their outer surfaces, but they continue to move downward along the distal gonangium epithelia and through the passageways to the germinal vesicle area of the egg. As the spermatozoa move deeper into the gonangium the 640–700 Å membrane‐bounded (“pro‐acrosomal”) vesicles of the sperm progressively decrease in number. By the time the spermatozoa reach the egg, 88% of the vesicles have been lost. It is possible that the contents of the vesicles play a role in the control of spermatozoan‐epithelial cell adhesion or that they serve, in some way, to permit sperm penetration to the egg surface. Alternatively, their loss may be a morphological indication of the capacitation‐like interaction between the sperm and normal female gonangium epithelial cells which is required for fertilization in Campanularia flexuosa.
Surgical approach to the dolphin's ear
Authors: Ridgway Sam H. , McCormick James G. , Wever Ernest Glen 
Published: June 2005

AbstractA surgical approach to the cetacean (Tursiops truncatus and Lagenorhynchus obliquidens) ear represented a unique problem. The first obstacle was the development of a safe and humane anesthesia procedure and techniques of long‐term physiological maintenance of the animal during surgery. The surgical anatomy was a challenge especially because of the extensive venous plexuses that invest the entire ear and adnexa. The corpus cavernosum carotidis and other small arterial networks course through this venous mass.Sodium pentothal‐halothane anesthesia and careful physiological monitoring were determined to be adequate for long‐term maintenance during surgery and cochlear recording experiments. A specially designed surgical tank held the animal during the procedure. Immersion in water relieved the lungs of external pressure that ordinarily occurs, when the animal is out of the water, due to the flexible thorax. Thermoregulation was provided for by regulating the water temperature in response to the dolphin's core temperature. This arrangement also provided for underwater auditory stimulation and easy manipulation of the animal since dolphins with their lungs inflated are close to neutral buoyancy.It was necessary to ligate the external and internal carotid arteries, neither of which supplies blood to the ear or brain. Hemostasis in the massive venous plexus could be achieved only by partial removal and subsquent application of oxycel and surgical cement to effectively dam off the area of the round window and other ear structures for electrical potential recording and experimental manipulations.With this technique the round window of the cochlea was exposed. Fully anesthetized animals were maintained for periods up to 24 hours while electrophysiological measurements were being made. Some of the auditory measurements required further surgical manipulation of the auditory meatus, bulla, ossicular chain and other middle‐ear structures.
Development of the rat salivary glands. III. Mesenchymal specificity in the morphogenesis of the embryonic submaxillary and sublingual glands of the rat
Authors: Ball William D. 
Published: June 2005

AbstractThe parotid, sublingual and submaxillary buds of the embryonic rat can undergo typical morphogenesis in response to capsular mesenchyme from either the parotid or submaxillary‐sublingual rudiment. The submaxillary epithelium can be induced by embryonic bronchial mesenchyme to undergo limited morphogenesis, while the sublingual epithelium exhibits more extensive morphogenesis in response to the same stimulus. Pancreatic mesenchyme and jaw mesenchyme are essentially inactive in inducing the submaxillary epithelium, but can consistently stimulate morphogenesis of the sublingual rudiment at a relatively low level of complexity. Thus, the sublingual rudiment shows a less‐stringent mesenchymal requirement than does the submaxillary, and with both rudiments, lung mesenchyme is more effective than pancreas or jaw mesenchyme in supporting morphogenesis.
Incorporation of 3H‐thymidine in rhesus monkey (Macaca mulatta) embryos
Authors: Sawyer R. H. , Wilson D. B. , Anderson J. , Hendrickx A. G. 
Published: June 2005

AbstractA procedure has been developed whereby cell proliferation during early embryogenesis of the monkey can be studied radioautographically following in vivo exposure to relatively small amounts of 3H‐thymidine.
Lysosomes and lysosomal enzyme activity in the regenerating planarian; Evidence in support of dedifferentiation
Authors: Coward S. J. , Bennett C. E. , Hazlehurst B. L. 
Published: June 2005

AbstractThe lysosomal enzyme acid phosphatase has been shown to increase in activity rapidly during the first 12 hours of cephalic regeneration in the planarian Dugesia dorotocephala. This increase was correlated with the cytological demonstration of lysosomes in dedifferentiating cells and the electron microscopical cytochemical localization of acid phosphatase in lysosomes. These findings are interpreted as being consistent with the dedifferentiation hypothesis for the origin of blastema cells.
Length, weight and secondary sex character development in male and female phenotypes in three sex chromosomal genotypes (XX, XY, YY) in the killifish, Oryzias latipes
Authors: Fineman Robert , Hamilton James , Chase Gary , Bolling David 
Published: June 2005

AbstractLength and weight of medaka appeared to be influenced by sex hormone‐treatment and genotype. Hormone‐treated genotypes were significantly shorter in length and slightly lighter in weight than untreated genotypes. The degree of response to androgenic and estrogenic treatment appeared to be strongly influenced by genotype. Growth of XX fish was stunted more by androgenic treatment than by estrogenic treatment. Growth of XY and YY fish was stunted more by estrogenic than by androgenic treatment. Differences in the metabolism of sex hormones by the three genotypes might be responsible for the variation in response to androgenic or estrogenic treatment. Sex phenotype, a unique interaction between genotype and exogenous hormone‐treatment, strongly influenced secondary sex character development (relative papillary size and number).
Binding of antibody to LDH‐X by the mouse blastocyst
Authors: Bene Michelle , Goldberg Erwin 
Published: June 2005

AbstractLDH‐X from spermatozoa can be demonstrated within the perivitelline space and zona pellucida of the preimplantation mouse embryo. Peroxidase reaction product is deposited in these areas of blastocysts incubated with rabbit anti‐LDH‐X IgG and then with peroxidase labelled goat anti‐rabbit IgG. Unfertilized ova do not bind antibody to LDH‐X.
Morphological substrates of conduction in the colonial hydroid Hydractinia echinata. I. An ectodermal nerve net
Authors: Stokes Darrell R. 
Published: June 2005

AbstractCorrelative light and electron microscope observations suggest that the colonial hydroid, Hydractinia echinata, possesses a single ectodermal nerve net in gastrozooid and dactylozooid polyps, and in the uppermost ectodermal sheet of the basal mat, but not in free stolon tips. Two distinct cell types comprise this nerve net — ganglion cells and sensory cells, the neurites of which characteristically possess microtubules and electron dense, membrane‐bound vesicles. The sensory cell body possesses an apical ciliary apparatus which distinguishes it from the ganglion cell type. Ultrastructural features of ganglion and sensory cells are presented in relationship to their distribution. Gastrozooids and the basal mat contain ganglion and sensory cells; dactylozooids contain ganglion cells primarily on the concave side of the polyp. Significantly, distinct bundles comprised of several neurites are found directly above the epithelio‐muscular cell processes of the gastrozooid and dactylozooid. Although synaptic junctions have not been found between ectodermal nerve cells and the muscle processes, they have been found bridging two nerve cells.
Investigations on the function and hormonal regulation of the anal appendices in Blennius pavo (risso)
Authors: Laumen Johannes , Pern Uwe , Blüm Volker 
Published: June 2005

AbstractThe appendices of the first and second anal fin spines of mature males of the mediterranean Blennid fish, Blennius pavo, produce a pheromone which attracts females of the same species. Evidence for this is provided by the observation that water from aquaria in which mature males have been kept is strongly attractive to female fish. However, aquarium water from females or from immature males, whose anal appendices are poorly developed, is without effect. Aquarium water from immature males that had been treated with luteinizing hormone at a concentration of 0.15 mg/g bodyweight, but not higher, is effective in attracting females. Such LH treatment leads to enlargement of the anal appendices and to a proportional increase in the behavioral reactions of female fish brought into contact with aquarium water from such treated males. Aquarium water from males whose anal appendices have been removed by surgery or cautery does not elicit behavioral reactions from female fish. Histological examination of the anal appendices reveals the presence of numerous tubular invaginations in the epidermis. It is conjectured that pheromone production is related to the proliferation and degeneration of epidermal cells which can be seen to occur in the tubular structures. The pheromone(s) appears to be produced phasically during spawning under the direct influence of hypophyseal gonadotropin.
DNA synthesis without mitosis in amputated denervated forelimbs of larval axolotls
Authors: Tassava Roy A. , Bennett Leo L. , Zitnik Gaylynn D. 
Published: June 2005

AbstractBoth forelimbs of axolotl larvae were amputated at the elbow and left limbs were immediately denervated. Both the left and right limbs of 4 larvae/day were examined for DNA synthesis (H3‐thymidine‐autoradiography) and mitotic index on days 1 to 7 post‐amputation. DNA synthesis was evident in both innervated regenerating, and denervated non‐regenerating limb stumps, on days 4, 5, 6, and 7. Mitotic index increased only in innervated limbs, beginning on day 5.
Ultrastructure of the development and subsequent breakdown of muscle in aneurogenic limbs (Ambystoma)
Authors: Tweedle Charles D. , Popiela Heinz , Thornton Charles S. 
Published: June 2005

AbstractA study, mainly by electron microscopy, has been made on the forelimb musculature of Ambystoma opacum larvae following removal of the presumptive limb innervation in the embryo. In the aneurogenic limbs, early development and differentiation of striated muscle occurs at the same rate as in normal animals. At the time of nerve ingrowth into the normal limb, both myotubes and differentiated myofibers of small diameter are present. With the failure to make contact with nerves, the aneurogenic muscle does not advance beyond the early myofiber stage and soon (1–2 weeks) begins to show signs of atrophy. As has been described in studies of denervated adult muscle, the breakdown seems to be in two phases overlapping in time. In the first, a degenerative autolysis takes place, leading to loss of striation. There is dissolution of the Z bands, followed by disorder of the myofilaments. During this process there is evidence of fragmentation of the muscle fiber, both into nucleated and anucleate portions; waste sarcoplasm is thought to be discarded into the intercellular spaces. Interestingly enough, with the techniques used, no sign of lysosomes was noted and only a few macrophages were seen. The second phase of muscle breakdown is one with characteristics of atrophy, where single myofibers undergo gradual reduction in diameter. This process seems to take place by detachment of filaments from the periphery of the fibers and by their subsequent breakdown in the interfibrillary spaces. Late stages of muscle deterioration show large areas of cytoplasm containing scattered ribosomes, small vesicles, and a few mitochondria. The final picture is of densely stained irregular nuclei surrounded by a thin rim of cytoplasm; the intercellular spaces contain a considerable amount of fibrous material. The cartilage and skin of the aneurogenic limb appear normal even after the latest stages of muscle deterioration.
Forebrain localization of the spawning reflex response to exogenous neurohypophysial hormones in the killifish, Fundulus heteroclitus
Authors: Macey Michelle J. , Pickford Grace E. , Peter Richard E. 
Published: June 2005

AbstractStereotaxically placed electrolytic lesions were made in six areas of the forebrain of killifish, Fundulus heteroclitus. Lesioned fish were tested for their ability to respond to intraperitoneal injections of hog posterior pituitary suspension or synthetic arginine vasotocin, administered at doses that ensured occurrence of the spawning reflex response in unoperated controls. Only lesions that destroyed a major part of the nucleus preopticus severely impaired, or abolished, the spawning reflex response.
The chemical ecology of Biomphalaria glabrata (say): The effects of media homotypically conditioned by adult snails on the growth of juveniles
Authors: Thomas J. D. , Aram R. H. 
Published: June 2005

AbstractHomotypically conditioned media (Hom. C.M.) produced by adult Biomphalaria glabrata weighing about 600 mg and fed on pure cellulose under bacteriostatic conditions at a density of one snail per 100 milliliter of standard snail water for three days significantly enhanced the growth of juveniles. Hom. C.M. produced under the same conditions by fasting snails that were previously fed on lettuce, also had a growth promoting effect but was less potent. The growth promoting factors have a molecular weight of 500‐104, and appear to act directly on the snails and not indirectly by influencing the food medium. The extent to which absolute growth rate is stimulated by the growth factors correlates well with decrements in the conductivity and calcium concentration of the media. Possible modes of action of the growth factors are discussed. They appear not to influence the relative weights of shell, or body and water content of the snails. It is suggested that the adaptive significance of the growth factors is to facilitate rapid increase in numbers of this gregarious and often fugitive species when environmental conditions are favorable.