bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of eyestalk removal in crabs: Relation to normal premolt
Authors: Spaziani Eugene , Ostedgaard Lynda S. , Vensel William H. , Hegmann Joseph P. 
Published: June 2005

AbstractThirty‐six measured variables were compared in crabs de‐eye‐stalked (DE) for 24 hours to 45 days and with normal animals well advanced in the premolt stage of the molting cycle. DE crabs generally differed from premolts in water and ion composition of carapace and blood, but not in organ water content, and differences were independent of time after DE. Furthermore, acute (24‐hour) DE animals displayed 30‐fold higher uptake of cholesterol‐14C in Y‐organs (four to fivefold higher in hepatopancreas and hypodermis) than premolts; uptakes dropped to premolt levels in long‐term DE animals. It is concluded that acute and long‐term de‐eyestalking induce abnormalities in several physiological parameters but also induce changes in cholesterol processing suggestive of normal early and late premolt stages, respectively.
Cellular proliferation in the skin of x‐rayed newt limbs (with a note on x‐ray‐induced limb regression)
Authors: Wertz Richard L. 
Published: June 2005

AbstractLeft hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x‐rays that inhibited regeneration (2,000 R). This x‐ray dose and other doses (700‐2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x‐ray‐induced degeneration of the limbs had ended. Proliferative activity in x‐ray limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x‐ray‐induced limb regression had ended showed levels of [3H]‐thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P ≪ 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P ≪ 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x‐rays. However, levels of normal cell division were observed after amputation or after cessation of x‐ray‐induced limb regression.
Properties of an oviducal protein involved in amphibian oocyte fertilization
Authors: Miceli Dora C. , Fernandez Silvia N. 
Published: June 2005

AbstractThe secretion produced at the most cephalic portion of the oviduct of the toad (pars recta in Bufo arenarum) is involved in fertilization. Although the present study indicates that a prerequisite for the fertilization of coelomic eggs is either their passage through the pars recta (PR) or their treatment with PR secretion fluid prior to insemination, the exact role of this secretion in the fertilization process is still not clearly understood. A protein acting upon the vitelline envelope (VE) of Bufo arenarum coelomic eggs has been purified from secretion fluid (pars recta protein, PRP). Some properties of both this protein and the secretion fluid are examined in an effort to understand their mechanism of action. It was shown that PRP partially dissolves the VE of coelomic oocytes in a way that resembles the action of proteolytic enzymes. PRP has also proved to be active on synthetic substrates of proteolytic enzymes such as p‐Tosyl‐L‐arginine methyl ester‐HCl (TAME), α‐N‐benzoyl‐L‐arginine ethyl ester‐HCl (BAEE), and α‐N‐benzoyl‐DL‐arginine‐p‐nitroanilide HCl (BAPNA). PR enzyme is activated by calcium ions, shows a broad peak of maximum activity at pH 7.8, is stable at alkaline pH, and is inhibited by soybean trypsin inhibitor (SBTI) and N‐α‐p‐tosyl‐L‐lysine chloromethyl ketone HCl (TLCK) but not by lima bean trypsin inhibitor (LBTI) or L‐1‐tosyl‐amide‐2‐phenylethylchloro‐methyl‐ketone (TPCK).
Sperm nuclear decondensation in Barnea candida (Mollusca, Pelecypoda) oocytes does not require germinal vesicle breakdown
Authors: Dubé FrançLois , Dufresne‐Dubé Louise , Guerrier Pierre 
Published: June 2005

AbstractBarnea candida oocytes, submitted to D‐600 (100 μM) 15–20 seconds after insemination in order to inhibit Ca++ uptake but not acid release, fail to exhibit germinal vesicle breakdown (GVBD) whereas penetrated spermatozoa are able to decondense normally. Oocytes transferred in 100 mM Na‐acetate seawater at pH 6.3, 1 minute after insemination, in order to inhibit acid release, fail to undergo GVBD and sperm nuclear decondensation. Upon return of these oocytes to normal seawater and treatment with an excess of KCl, they exhibit GVBD and decondensed sperm nuclei are seen within their cytoplasm. These results show that sperm nuclear decondensation does not require GVBD or Ca++ uptake but may be related to an intracellular pH increase.
Significance of periodic fluctuations in the haemolymph proteins and their catabolic products during starvation and repeated injury in Scylla serrata (Forskal)
Authors: Subhashini M. H. , Ravindranath M. H. 
Published: June 2005

AbstractThe fate of haemolymph proteins during the course of prolonged starvation was investigated. Two different experimental protocols were set up. In experiment 1, sampling of the haemolymph was done in a group of six crabs at 3‐day intervals up to 33 days (group 1). In experiment 2, separate groups of crabs were sampled at 3‐day intervals up to 33 days (group 2).There is no change in body weight. The haemolymph volume and water increase significantly indicating hydration of haemolymph. The haemolymph protein concentration and quantity decline significantly in both groups during the course of prolonged starvation. Concomitantly, the haemolymph free amino acids concentration and quantity increase in both the groups, indicating degradation of protein during the course of starvation.That degradation of protein cannot occur continuously but rather takes place on specific days in both groups is indicated by the increase in the products of protein catabolism—namely, free amino acids and ammonia. The results also provide evidence for the mobilization of proteins from storage sites. Nonprotein dry weight increases markedly during the course of starvation, the significance of which is discussed.
Timing of X‐chromosome inactivation is stage dependent rather than age dependent
Authors: Kratzer Paul G. 
Published: June 2005

AbstractThe timing of X‐chromosome inactivation was compared in two mouse strains that differ in their rates of development. The occurrence of X inactivation was measured by dosage changes for the X‐linked enzyme hypoxanthine phosphoribosyl transferase. It was found in intrastrain and reciprocal hybrids that X inactivation was dependent on morphological stage and not on the age of the embryo.
Purification and physical properties of arginase from Xenopus laevis
Authors: Peiser Liora , Balinsky John B. 
Published: June 2005

AbstractArginase from the liver of Xenopus laevis has been purified to homogeneity by heat treatment, acetone fractionation, and isoelectric focussing. The main component had an isoelectric point (I.E.P.) of 7.3; there is a minor component of I.E.P. 7.8. The molecular weight of the enzyme, as determined by gel filtration on Sephadex G200, is 76,000 daltons, substantially less than that of rat liver arginase studied concurrently. The molecular weight of the subunits, as determined by electrophoresis in sodium dodecyl sulfate, is 18,000 daltons, again less than that of rat liver arginase. The data indicate that Xenopus liver arginase, like rat liver arginase, is a tetramer. The molecular weight of arginase from adult Xenopus laevis corresponds to that from larval Rana esculenta.
Characterization of spermatid/sperm basic chromosomal proteins in the genus Xenopus (Anura, Pipidae)
Authors: Mann M. , Risley M. S. , Eckhardt R. A. , Kasinsky H. E. 
Published: June 2005

AbstractSpermatid/sperm basic chromosomal proteins from 17 species and subspecies of the genus Xenopus (Anura, Pipidae) were compared. Electrophoresis on acetic acid/urea/Triton X‐100 polyacrylamide gels revealed that each Xenopus species with a diploid chromosome number of 36, 72, or 108 showed multiple, diverse spermatid/sperm‐specific basic chromatin proteins with mobilities greater than the somatic histones. The numbers and mobilities of these proteins were characteristic of each Xenopus species and each subspecies of Xenopus laevis. Cytochemical tests revealed that the sperm basic nuclear proteins of these Xenopus species and subspecies were rich in arginine and lysine and contained more arginine than the nuclear proteins of somatic cells.X. tropicalis (2n = 20) and X. sp. n. (Zaire) displayed spermatid/sperm‐specific basic chromatin proteins which migrated within the histone H1 region of acetic acid/urea/Triton X‐100 polyacrylamide gels. Cytochemically the sperm nuclei of these species resembled those of somatic cells.These observations suggest that spermatid/sperm basic nuclear proteins can be used as molecular markers for individual species and subspecies of the genus Xenopus.
Water balance and apparent oocyte resorption in desert millipedes
Authors: Crawford C. S. , Warburg M. R. 
Published: June 2005

AbstractOosorption in response to desiccation stress was tested in spirostreptid millipedes from arid environments. Seasonally collected and experimentally stressed adult females were examined for penetration of oocytes by trypan blue, for compartment levels of water in cuticle + tissue and gut + gut contents, and for hemolymph osmolalities.Archispirostreptus syriacus from the winter‐rainfall Judaean and Negev deserts decreased in total body water during the hot dry summer. Simultaneously, water in cuticle + tissue and in gut + gut contents increased and decreased respectively in proportion to total water. Water in both compartments decreased in starved specimens exposed for 19 days to 76% relative humidity; these millipedes resorbed a higher percentage of oocytes than did field controls but not more than specimens in saturated air.Groups of starved premolt (spring) and postmolt (summer) Orthoporus ornatus from New Mexico (summer rainfall) each responded differently when exposed to humidities found in their respective habitats. Compartment water levels in the former remained constant for 19 days under moderate conditions; they declined in the latter after 36–42 days of relative moisture stress. Neither stage showed increased oosorption over field controls when exposed to seasonal humidity ranges.Archispirostreptus syriacus resorbed a higher proportion of oocytes than did O. ornatus, which matured oocytes only in summer rather than most of the year. Patterns of oosorption and oocyte development probably reflect species‐specific life histories and relative states of starvation rather than seasonal water balance and desiccation stress.
Mechanisms of water vapor absorption in insects
Authors: Machin John , O'Donnell Michael J. , Coutchié Pamela A. 
Published: June 2005

AbstractVapor absorption is the mechanism by which specially adapted terrestrial arthropods expend energy to escape from conventional equilibria, dictated by the difference between water activity of the body fluids (aw = 0.99) and the environment. vapor absorbers have an identifiable “condensing” or “carrying” fluid compartment with significantly lower activity. The sites of vapor uptake may be limited to mouth or rectal regions because the mechanisms have probably evolved by modifying existing water transport systems. Morphometric analysis of condensing structures have helped understand the vapor uptake mechanism in Arenivaga and tenebrionid larvae. Activity lowering of condensing fluid is accomplished either by solute‐independent capillary condensation or by solute transport. Linear absorption kinetics, shown by the better‐known vapor absorbers, is achieved by flow‐modulated fluid or ion transport. Comparative studies may help identify anomalous uptake mechanisms worth further study and predict where other examples of the phenomenon may be found.
Pattern regulation during regeneration of embryonically produced symmetrical forelimbs in the axolotl, Ambystoma mexicanum
Authors: Tank Patrick W. 
Published: June 2005

AbstractEmbryonic axolotls (Stages 32–34) underwent surgery during which a graft of flank tissue was transferred from a donor animal to the anterior margin of the forelimb field in a host animal. Double‐posterior forelimbs containing from one to eight digits developed. These limbs were amputated at a level proximal to the elbow to assess their regenerative ability. The majority (62%) of these limbs failed to regenerate externally visible structures. Symmetrical limbs bearing five digits or more than five digits regenerated with greatest frequency (54%). Symmetrical forelimbs bearing four digits or fewer than four digits regenerated less frequently (31%). All regenerates displayed double‐posterior symmetry and usually contained fewer digits than were present in the original limb. The significance of these findings is discussed in the context of a current model for pattern regulation in epimorphic fields.
Enzyme clusters during the metamorphic period of Ambystoma mexicanum: Role of thyroid hormone
Authors: Lamers Wouter H. , Mooren Piet G. , De Graaf Andre , Charles Rob 
Published: June 2005

AbstractEnzyme activities and DNA content have been measured in axolotl liver during the metamorphic period (4–8 months after spawning). Three different types of enzyme activity profiles were observed. In the type I profile (carbamoyl‐phosphate synthase, arginase, ornithine transcarbamoylase, and glutamate dehydrogenase) enzyme activity is high in the youngest animals studied, and shows a minimum at 5 months followed by a maximum at 8 months of age. Thereafter activities do not change or slightly decrease. In the type II profile (tyrosine aminotransferase, glucose–6–phosphatase) enzyme activity shows a peak at 5 months of age and is low thereafter. Hexokinase, the enzyme with a type III profile, shows high activity throughout the metamorphic period. DNA content remains high throughout the metamorphic period but decreases 50% between 9 and 12 months of age, probably due to an increase in the size of the hepatocytes. No glucokinase activity was detected. High activities of cluster II enzymes represent early metamorphic events, while the rising part of cluster I is associated with late metamorphic events.The apparent molecular specific activity increases during natural development between 5 and 9 months of age, or precociously, upon thyroid hormone treatment. This change in apparent molecular specific activity is correlated to the advent of ureotelism.
Cytochemical localization of adenylate cyclase activity in planarian tissues
Authors: Pascolini Rita , Gargiulo A. M. , Spreca A. , Ceccarelli P. 
Published: June 2005

AbstractCytochemical studies of adenylate cyclase activity were performed on Dugesia lugubris s.l. to ascertain which cell types, among the heterogenous cell population, showed significant adenylate cyclase activity on their plasma membranes.Nondecapitated worms and cephalic regenerants were examined in replicated experiments. Evidence of adenylate cyclase activity was noted in secretory tissues and the protonephridial system of non‐operated worms, and also in dedifferen‐tiating and regenerating tissues of operated worms. Observations presented in this study call attention to the role of adenylate cyclase in some of the main physiological processes of triclads, such as secretion, excretion, and regeneration.
Dimensionality and contractile vacuole function in ciliated protozoa
Authors: Lynn Denis H. 
Published: June 2005

AbstractIt is believed by some (Günther, '75a) that the dimensional theory of biological similarity is somehow not appropriate at the microscopic and cellular levels. The results of the present study of contractile vacuoles of ciliated protozoa, ranging in length from 25 to 150 μm, sugggests, however, that the theory is appropiate. The data demonstrate that 1)the expected strong negative correlation exisots between frequency of contraction and cell size, and 2) that the expected positive correlation exists between volume output of the vacuole and cell size. An additional experiment indicates the improbability of Tucker's hypothesis ('71) that the epiplasmic layer provides a barrier to water flux through the cell cortex.
Stroboscopic illumination for the assessment of hyperactivated montility of mouse spermatozoa
Authors: Cooper T. G. , Woolley D. M. 
Published: June 2005

AbstractSpermatozoa showing hyperactiveated motility can be recognized in multie‐exposure micrographs. The cells were confined in 10‐μm‐deep chambers, illuminated in darkfield conditions, and photographed using a stroboscope (10 Hz) Hyperactivitation, as judge from the pattern of ten superiemposed images, coul be promoted by raising the ionic strength of the medium but did not occur in the absence of calcium.
Mutants of Caenorhabditis elegans with dumpy and rounded head phenotype
Authors: Hosono Ryuji , Hirahara Katsumi , Kuno Sigeru , Kurihara Takayuki 
Published: June 2005

AbstractMutations bearing morphological alterations in both head and body are reported in Caenorhabditis elegans. Although most dumpy mutants so far isolated have shorter bodies with normal head form, the mutants presented in this paper have rounded heads in addition to dumpy bodies. On examination with light‐ and scanning electron microscopes, defects in organs attached to the tip of head were not detected. The mutations were mapped as alleles of the dpy‐20 gene on linkage group IV. Segregation of the head abnormality from dumpy body was not detected upon examination of over 10,000 descendants from heterozygous offspring (F1), produced by crossing mutant hermaphrodites with wild‐type males. Revertants of dpy‐20 (cn142) allele were found to be almost wild‐type in both head and other body morphology, supporting the possibility that both phenotypes in these alleles have been produced by a single mutation. Genetic analyses of two other revertants are also presented in this report.
The leg flexor muscle of Carcinus. II. Distribution of muscle fiber types
Authors: Parsons David W. , Mosse Peter R. I. 
Published: June 2005

AbstractThree types of muscle fiber were recognized in the leg flexor muscle of Carcinus maenas on the basis of histochemical staining for the oxidative enzyme NADHD and analysis of fiber cross‐sectional area. The distribution of these fiber types within the muscle is described. The oxidative capacity and cross‐sectional area of the fiber was correlated with the fiber type determined physiologically.
Developmental aspects of hexose metabolism in Bufo bufo
Authors: Miranda Michele , Botti Dario , Pantani Claudio , Ragnelli Anna Maria , di Cola Mario 
Published: June 2005

AbstractDue to the close correlation between glucose mobilization and utilization within animal tissues, in this paper, the stages of appearance of phosphorylase, glucose‐6‐phosphatase and hexokinase as well as the levels of some intermediates of glucose metabolism have been investigated during Bufo bufo development. Phosphorylase first appears at stage 13 and is dominant in the neural part of the embryo, but, after this stage, increases relatively more in the nonneural one. Hexokinase appears at stage 17 and glucose‐6‐phosphatase soon after. Phosphorylase appearance at stage 13 is correlated with an increase of lactate content in the embryo; this may indicate a metabolization of hexoses. On this basis, the subsequent appearance of hexokinase and glucose‐6‐phosphatase activities also seems coherent with hexose mobilization and utilization within embryo. No direct causative factor for the changes observed was evident.
Effect of environmental temperature on the incorporation of 3H‐ethanolamine into the phospholipids of the tissues of the crab Carcinus maenas
Authors: Chapelle S. , Brichon G. , Zwingelstein G. 
Published: June 2005

AbstractIncorporation of 3H‐ethanolamine in phosphatidylethanolamine (PE) and in phosphatidylcholine (PC) isolated from different tissues of crab Carcinus maenas was analyzed at environmental temperature of 13°C and 23°C. The stepwise N‐methylation of PE to PC occurs only in the hepatopancreas, its importance being greater in animals living at 23°C. The hemolymph‐hepatopancreas exchange of PC plays an important part on the regulation of the hepatopancreas PC pool. Also, the environmental temperature strongly influences PC distribution between hemolymph and hepatopancreas.
Adhesion of osteoclasts and monocytes to developing bone
Authors: Martini Mary C. , Osdoby Philip , Caplan Arnold I. 
Published: June 2005

AbstractOsteoclast resorption of bone matrix during bone development is preceded by cell attachment to bone. An in vitro assay is described that measures adhesion of isolated osteoclasts and their presumed progenitor cell, the monocyte, to embryonic chick bone. Osteoclasts were isolated from day 19 chick tibia and enriched. Circulating chick hatchling monocytes were purified by Ficollhypaque sedimentation and attachment to plastic. Isolated cells were labeled with (32P)‐KH2PO4 to quantitate cell attachment. In one series of experiments, labeled cells were inoculated into vessels containing day 19 tibias with either endosteal or periosteal bone surface exposed. Labeled cells were also inoculated into chambers containing day 6 (cartilage cores), day 12 (bone and cartilage cores), or day 19 embryonic tibias (bone). Cultures of stage 24 chick limb mesenchyme and embryonic chick skin fibroblasts served as controls. Results demonstrate that twice as many osteoclasts and monocytes adhere to bone as compared to fibroblasts and stage 24 limb mesenchymal cells. Furthermore, there does not appear to be selective adhesion to the endosteal as compared to periosteal bone surfaces. When the data is calculated on the basis of cell attachment per area of each substrate, the day 12 cores had slightly higher number of osteoclasts and monocytes attached compared to day 19 bones; day 6 cartilage cores bound few cells. These observations suggest that osteoclasts and monocytes have a high affinity to bone which seems to be influenced by the developmental age and composition of the substrate.