bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absence of maternal proteins in 5–7‐day blastocyst fluid indicates limited protein passage before implantation
Authors: Kulangara Abraham C. 
Published: June 2005

AbstractRabbit serum albumin (RSA) and gamma globulin (RGG) were measured in fluid collected from single 5, 5.5, 6 and 6.5‐day blastocysts of New Zealand White rabbits, using a radial immunodiffusion method capable of detecting a minimum of 2–5 μg/ml in 1 μl. The samples showed little or no RSA and RGG. Three sources of contamination in fluid collection were identified. They are, blastocyst contact with aqueous solutions used to flush them out or rinse them, carrying in of surface proteins by pipette tips and withdrawal of trophoblast from lemmas. It is shown that fluid collected without precautions to avoid contamination will contain uterine fluid constituents.Bovine serum albumin (BSA), RSA and RGG pass readily into blastocyst fluid in vitro and after intrauterine injection. However, such passage is abnormal because BSA does not appear in 5–7‐day blastocyst fluid after intravenous injection of the mother (Kulangara and Crutchfield, '73) and normal 5–7‐day fluid shows little or no RSA and RGG. High viscosity and pH in the normal uterine lumen greatly reduce protein passage so that only traces reach trophoblast cells, which seem to digest this protein with lysosomal enzymes and/or transport it outward, thereby maintaining a virtually protein‐free blastocyst fluid, prior to implantation. Restriction of protein passage appears to be essential, since normal development is interrupted by intrauterine injections.
Phenogenetics of a suppressor and an enhancer gene of the lozenge34k allele of Drosophila melanogaster
Authors: Beeson Virginia S. , Bender Harvey A. 
Published: June 2005

AbstractThe recessive sex‐linked gene, lozenge34k was initially identified on the basis of its effect on the compound eye of Drosophila melanogaster. However, its pleiotropic effects include modification of the antennae, legs and female reproductive structures as well. Two modifier genes, a third chromosome suppressor, su(lz34k), and a fourth chromosome enhancer, spae(lz), have been previously described and their effects on the various mutant characters of the lozenge34k phenotype were the basis of this study. These investigations included scanning electron microscope observations of the external morphology of the compound eye, a quantitative determination of the effects of the mutant genes on the tarsal claws, antennae and female reproductive capacity, and an examination of the functional ability of the compound eye. It was found that the modifier genes had little effect on the aspects of the lozenge34k phenotype other than the compound eye. The enhancer seems to suppress the lozenge phenotype with regard to the length of the antenna but otherwise there is no effect of the modifiers with regard to antennae, tarsal claws, spermathecae or female reproductive capacity (the number of eggs oviposited or the number of adult progeny ensuing from females tested). The lozenge‐enhanced males also differed significantly from the other types in being less successful at inseminating females in the light. The lozenge and lozenge‐suppressed males were more successful than the lozenge‐enhanced but less so than the wild type. This can be related to their ability to “see” since in the dark all types were at an equal disadvantage. Wild flies exhibited a positive phototactic response, lozenge were significantly less responsive, and both the suppressed and enhanced flies were even less so. Compound‐X females lacking the lozenge34k allele were tested for phototaxis. Those homozygous for the suppressor were significantly less phototactic than the others indicating that the suppressor alone has a phenotype at this level. Except for the phototactic response of lozenge‐suppressed flies, the functional ability of the compound eye can be correlated with its morphology.
Acetylcholinesterase in singly and multiply innervated muscles of normal and dystrophic chickens. II. Effects of denervation
Authors: Linkhart T. A. , Wilson B. W. 
Published: June 2005

AbstractNeural regulation of mature normal fast twitch muscle of the chicken suppresses high activity, extrajunctional localization, and isozyme forms of acetylcholinesterase (AChE) characteristic of embryonic, denervated and dystrophic muscle. Normal adult slow tonic muscle of the chicken retains intermediate levels of activity and embryonic isozyme forms but not extrajunctional activity; it is not affected by muscular dystrophy. The hypothesis that neural regulation of the AChE system is lacking in slow tonic muscle and thus not affected by dystrophy was tested by denervating the fast twitch posterior latissimus dorsi and slow tonic anterior latissimus dorsi muscles of normal and dystrophic chickens. Extrajunctional AChE activity and embryonic isozyme forms increased, then declined, in both muscles. The results suggest that control of AChE is qualitatively similar in slow tonic and fast twitch muscle of the chicken.
The function of hemocyanin in respiration of the blue crab Callinectes sapidus
Authors: Mangum C. P. , Weiland A. L. 
Published: June 2005

AbstractBlood PO2 in the blue crab Callinectes sapidus, a very active species of tropical origin, is lower at 22°C than that of larger crabs in colder waters. These low oxygen levels permit its hemocyanin to be highly oxygenated at the gill, and to deliver almost half of its oxygen to the tissues in resting animals. Sustained muscular activity results in conspicuous decreases in blood PO2, pH and hemocyanin oxygenation. Although the venous reserve is fully utilized, hemocyanin oxygenation at the gill decreases so much that there is no change in its total quantitative function. The large Bohr shift becomes functional during activity, but its quantitative importance is not clear.
The neural control of contraction in a fast insect muscle
Authors: Josephson Robert K. , Stokes Darrell R. , Chen Victor 
Published: June 2005

AbstractThe wing muscles used in singing by the katydid, Neoconocephalus robustus, are extraordinarily fast. At 35°C, the animal's thoracic temperature during singing, an isometric twitch lasts only five to eight msec (onset to 50% relaxation) and the fusion frequency of these muscles is greater than 400 Hz. Stimulating the motornerve to a singing muscle initiates a short (2.5 msec at 35°C), sometimes overshooting depolarization of the muscle fibers. Despite their spike‐like appearance, the electrical responses are largely synaptic potentials. The muscle membrane appears to be capable of only weak, electrically‐excitable, depolarizing electrogenesis. The short synaptic potentials result in part from rapidly‐developing delayed rectification, in part from a low resting membrane resistance (Rm = 162 Ωcm2) and a concomitantly short membrane time constant (about 1.5 msec).
In vitro regression of cement gland epithelium from Xenopus laevis
Authors: Lyerla Timothy A. 
Published: June 2005

AbstractThe development of Xenopus laevis cement gland ectoderm cultured as epidermal vesicles from neurula stage embryos is described. The life cycle explanted gland cells closely parallels that seen in intact animals. The cells increase in height, extrude their secretory mucin and most of the oocyte pigment granule inclusions, and then regress. The entire sequence takes from 16 to 21 days at 18°C. The vesicles show no obvious changes in general appearance after gland cell senescence and remain viable up to 35 days of culture. Cement gland development progresses normally then in the absence of any influences that might come from the embryo and appears to be an autonomous sequence of the gland cells once they begin to differentiate in early neurula stages.
The avoidance of D‐tryptophan by the nematode Caenorhabditis elegans
Authors: Dusenbery David B. 
Published: June 2005

AbstractIn chemotactic studies employing countercurrent separation the nematode Caenorhabditis elegans was found to avoid D‐tryptophan with a threshold in the range 10−4 to 10−3 M. There was no response to L‐tryptophan up to 10−2 M although it appeared to partially in hibit the response to D‐tryptophan.
Water states and water gates in osmotic processes, and the inoperative concept of molfraction of water
Authors: Scholander P. F. 
Published: June 2005

AbstractAn historical account is given of concepts regarding the mechanism of osmosis and imbibition, starting with Lord Kelvin's gravitational column, where he pointed out that a capillary standing in a dish of water within an isothermal enclosure must have a lowered vapor pressure at its elevated meniscus so as to match that emanating from the surface in the dish, otherwise distillation would violate the Second law. A brilliant sequence to this simple idea followed through Poynting, Arrhenius, Noyes and culminated with Hulett, who in 1901 formulated the “solvent tension theory” of osmosis, stating in essence that the thermal motion of the solute molecules by impact with the free solvent surface put the solvent under tension. This lowers the vapor pressure and thereby also its freezing point. Perrin, in famous experiments on Brownian motion, demonstrated solute‐solvent independence within a solution and further support came through Herzfeld, Mysels and Duclaux. We measured negative pressures in saltfree sap of mangroves and other plants matching the osmotic pressure in the leaf cells. A series of measurements on magnetic and gravitational effects on osmotic pressure likewise bore out the tension theory. The fashionable “water concentration theory” is left experimentally contradicted and in violation of the Second law.
The role of sex hormones in the growth of antler bone tissue. I: Endocrine and metabolic effects of Antiandrogen therapy
Authors: Bubenik G. A. , Bubenik A. B. , Brown G. M. , Wilson D. A. 
Published: June 2005

AbstractCyproterone acetate (CA), an antiandrogenic compound, was used in order to investigate the role of testosterone in bone growth processes. The formation of Haversian systems in the growing antlers of white‐tailed deer (Odocoileus virginianus) were substantially affected by only 3.5 mg of CA kg/wk. The mineralization processes of the bone matrix were almost completely blocked and the antlers persisted in growing throughout the whole year. Plasma levels of thyroxine, alkaline phosphatase and GH were higher while cortisol and testosterone levels were lower than in controls. No differences were registered in plasma levels of Ca, P or urea nitrogen. Despite hypertrophy of interstitial tissue, spermatogenesis was almost completely blocked. The sexual behaviour and the body appearance of experimental animals was typical for castrates.
Structural and functional heterogeneity in an insect muscle
Authors: Stokes Darrell R. , Josephson Robert K. , Price Rebecca B. 
Published: June 2005

AbstractSinging muscles of the katydid, Neoconocephalus robustus (Insecta, Tettigoniidae) are neurogenic, yet perform at contraction‐relaxation frequencies as high as 212 Hz (Josephson and Halverson, 71). The mechanical and electrical responses of different bands of one of these muscles (the dorsal longitudinal muscle, DLM) has been examined with respect to ultrastructurd features of each part which may be related to muscle performance. The DLM is composed of three bands and is innervated by four motoneurones. The cell bodies of three of these motoneurones occur ipsilaterally in the prothroracic ganglion; the cell body of the other motoneurone is contralateral in the mesothoracic ganglion. Three of the motoneurones (as yet unidentified fast axons) initiate extraordinarily fast twitches (rise time = 7.3 msec, half duration = 14.3 msec, 25 C), the fourth (an unidentified slower axon) evokes twitches which are considerably slower (rise time = 18.9 msec, half duration = 5.10 msec). Whereas the ventral and medial bands of the muscle are innervated only by fast axons (some fibers of the medial band are doubly innervated), the dorsal band is innervated by both a fast axon and the slower axon. A few fibers of the dorsal band are doubly innervated. The structure of fibers from the ventral and medial bands is very similar, with short sarcomeres (4.0 and 4.3 μm, respectively) and thin strap‐like myofibrils delineated by well‐developed sarcoplasmic reticulum (SR). Twenty‐four percent of the volume of ventral band fibers is SR and the diffusion distance from SR to the center of the adjacent myofibril averages 0.083 μm. Twenty percent of the medial band fiber volume is SR, with a diffusion distance of 0.118 μm. Ventral and medial band fibers contain about 40% mitochondria, and 33% myofibrils. The dorsal band fibers have longer sarcomeres (9.5 μm), and only 10% of the fiber folume is SR. The muscle fibrils of the dorsal band are larger and consequently the diffusion distance is greater (0.227 μm) than in the ventral and medial bands. Mitochondria comprise 23% of the volume of dorsal band fibers. Most dorsal band mitochondria are aggregated into distinct clumps. Although some dorsal band fibers are innervated by a fast axon and some by the slower axon, the dorsal band fibers are structurally homogeneous, suggesting that neurotrophic effects are not important in maintaining the structure of dorsal band fibers. The mechanical‐electrical performance and ultrastructure of the ventral and medial bands suggest their roll as fast, metabolically active but weak muscles, used in singing; the dorsal band as a slower but stronger muscle, perhaps involved in postural movements of the wing during singing.
Behavioral adaptation in neonatal chicks following embryonic vestibular system rearrangement
Authors: Heaton Marieta Barrow 
Published: June 2005

AbstractMicro‐surgery was performed on chick embryos during the second day of incubation (45–50 hours). Either one otocyst was removed or was rotated 180° and reimplanted. The chicks' behavior was studied for 1–13 weeks after hatching. The unilateral loss or rearrangement of vestibular (and auditory) input led initially to abnormal behavior patterns, usually consisting of poor righting reflexes, deficits in locomotion, balance and pecking accuracy, and a pronounced head nystagmus. However, in every case, these abnormalities were corrected within a few days after hatching, so that the operated animals became almost indistinguishable from normal controls. Histological evidence confirmed the extent of the loss of the vestibular and auditory structures and nuclear amalgams. The observed capacity of the neonatal chick to adapt to this sensory loss or disorientation is a rather rare example of infraprimate behavioral adjustment or modifiability, contrasting with the frequent demonstrations of behavioral rigidity in lower forms.
The proportional regulation of cortical structures in a hypotrich ciliate Paraurostyla weissei
Authors: Jerka‐Dziadosz Maria 
Published: June 2005

AbstractThe relationships between the size of a cell and the number of some compound cortical structures (cirri and membranelles) were studied using cells of a hypotrich ciliate Paraurostyla weissei stained with protargol. The length of cells was measured, the number of AZM membranelles, frontal, transverse and left marginal cirri were counted in cells from growing populations and in miniaturized cells obtained by starvation or repetitive regeneration.Changes in the number of cortical elements occur mainly through replacement of the whole ciliature during a morphogenetic process (division, reorganization, regeneration). In growing populations small postdividers and large predividers do not differ with respect to the number of membranelles and cirri despite the differences in size. In miniaturized cells the number of cortical elements formed decreases and is directly correlated with the length of the cell showing a proportional regulation in accordance to the cell size. Different modes of pattern regulation are discussed.
Changes in volume of the rhabdom in the compound eye of Aedes aegypti L.
Authors: Brammer J. D. , Clarin Bruce 
Published: June 2005

AbstractThe volume of the rhabdom in compound eyes of mosquitoes decreases upon illumination. This decrease is probably mediated by a bleaching of the visual pigment, since blue light is most effective in producing the change and red light is least effective. The reduction in rhabdom volume appears to be a result of rhabdomal membrane loss to coated vesicles and multivesicular bodies. These organelles were seen most frequently in blue adapted eyes, markedly less frequently in red adapted eyes, and only rarely in dark adapted eyes.
Mitosis in the intact and regenerating planarian Dugesia mediterranea n.sp. I. Mitotic studies during growth, feeding and starvation
Authors: Baguñà Jaume 
Published: June 2005

AbstractPlanarian neoblasts, the only cell type in this organism endowed with mitotic power, decrease in density as total body volume, total cell number, and length increase. Studies on mitosis show that the neoblast mitotic rate is a function of body length, being lower as the organism increases in length. The cephalo‐caudal distribution of mitotic figures in animals of different sizes shows a change towards a more even distribution of mitosis jointly with a mitotic increase in the caudal regions as length increases. However, in the sagittal and dorso‐ventral axes, the distribution of mitosis is always nonuniform, probably due to the uneven distribution of parenchymal tissue along them.The pharynx of animals in all size groups examined shows no mitotic figures except some near its base. This may suggest for this organ a proximal type of growth with some cell migration.Feeding elicits a very rapid increase in mitosis which lasts for almost a week, whereas long periods of starvation do not cause a significant increase or decrease in the basal mitotic rate. All these results stress the need of looking at the planarian neoblast mainly as a stem or replacement cell of most differentiated cell types and not as a mere “regeneration cell.” The implications of the results obtained for the mechanisms of growth and shrinkage are discussed.
Regional specialization for export protein synthesis in the male cricket accessory gland
Authors: Kaulenas M. S. 
Published: June 2005

AbstractThe accessory gland of the male cricket, Acheta domesticus, is a polytubular structure which produces a complex mixture of proteins used in the formation of the spermatophore. The synthetic capacity of individual accessory gland tubules has been analysed by micro‐scale SDS‐polyacrylamide gel electrophoresis. For the large and intermediate size tubules (approximately 300 in number), between 29 and 32 distinct protein synthetic patterns have been detected for individual tubules, with most of such patterns assignable to tubules at specific locations in the gland.Analysis of labelled nascent peptide distribution on polysomes confirms regional heterogeneity in protein synthetic capacity and also demonstrates a corresponding regionality in the distribution of active messenger RNAs. Other experiments indicate that tubules with identical products can have different extents of protein labelling, suggesting that a capacity to regulate either precursor uptake or protein synthetic rate exists at the level of the individual tubule.
Cleavage initiation activities of microtubules and in vitro reassembled tubulins of sperm flagella
Authors: Iwamatsu T. , Miki‐Noumura T. , Ohta T. 
Published: June 2005

AbstractCleavage of fish (Oryzias latipes) eggs was induced by injection of heterologous (sea urchin Hemicentrotus pulcherrimus and oyster Crassostrea gigas) sperm microtubules. Cleavage initiating (CI) activity of microtubules was higher in 3% PVP suspension than in 6% BSA, and not affected significantly by the concentration of microtubules themselves. The CI activity of microtubules suspended in 3% PVP was comparatively stable in the frozen state. Heat‐treatment at more than 55°C resulted in the loss of most or all of their CI activity. Such activity was observed in side‐by‐side aggregates of tubulin linear polymers of sea urchin (Hemicentrotus pulcherrimus) spermatozoa but not in dispersed linear polymers or tubulin dimers. Microtubules with CI activity seem to participate in initiating cleavage as astral centers, or a “seed” for polymerization of ooplasmic tubulins in activated eggs.
The relationship between blood PH, ammonia excretion and adaptation to low salinity in the blue crab callinectes sapidus
Authors: Mangum C. P. , Silverthorn S. U. , Harris J. L. , Towle D. W. , Krall A. R. 
Published: June 2005

AbstractThe output of ammonia increases in dilute waters in which blue crabs absorb Na+ against a gradient, but not those in which crabs remain in salt balance with the medium. Net acid output does not clearly vary with salinity. The balance between ammonia and urea output shifts towards ammonotelism at low salinity. These results, and the temporal responses of blood NH4+, Na+ and Cl‐after a salinity change, support the hypothesis that excess ammonia in blood plays an important role in osmoregulation as well as opposing the effect of salt reduction on the oxygen transport system.
Neurohemal organ extracts effect the ventilation oscillator in crustaceans
Authors: Berlind Allan 
Published: June 2005

AbstractExtracts of the pericardial organs of crabs injected into intact animals cause an increase in the frequency of scaphognathite beating. The active factor is not dopamine or 5‐hydroxytryptamine, which are present in pericardial organs; it is probably a peptide. The factor may represent a hormonal mechanism of coordinating heart rate and ventilation.
The sulfatides and some histochemical correlations of the lachrymal glands involved in salt secretion in Chelonia
Authors: Bolognani L. , Gerzeli G. , De Piceis Polver P. , Magnani P. 
Published: June 2005

AbstractHigh concentrations of sulfolipids (four fractions having different hexose/sulfate ratio), intense enzyme activity (ATPase, oxoreductases) and evidence of mucines (staining with PAS and Alcian blue) in intercellular spaces were found in the lachrymal glands of Caretta caretta and Malaclemys terrapin adapted to sea water. In addition, the supranuclear region of the gland cells in Malaclemys terrapin is filled with mucin granules.These biochemical and histochemical observations indicate that these glands have a function in salt secretion in both species and are also consistent with a function of mucous secretion exclusively in Malaclemys terrapin.Limited signs of hypotrophy are not accompanied by changes in concentrations of sulfolipids in Malaclemys terrapin adapted to fresh water; only the reactions for enzyme activities are less intense. The mucous secretion is not affected, whereas, in correlation with changes in salt secretion, the change in ATPase activity is most conspicuous.The correlations between the different components of the gland and salt secretion are compared with salt glands of birds and elasmobranchs.