bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Photoperiodic influence on growth in rats
Authors: Young D. A. B. 
Published: June 2005

AbstractIn otherwise identical conditions, weanling male rats were found to gain weight more slowly over a period of 5 to 6 weeks when the day length of artificial light was reduced from 12 hours by daily decrements of up to five minutes than when kept on a constant day length of 12 hours. In the several experiments performed the differences were highly significant and the overall reduction in weight gain was of the order of 10%. No appreciable changes were found in either food consumption or final body composition. No such difference in weight gain was observed in the same experiments when the animals were kept singly in cages, which caused a greatly increased food consumption and gain in weight. Rats kept on a constant day length of eight and one‐half hours showed the same weight gain as those kept on a 12‐hour day. The difference in weight gain was also found in a simultaneous comparison of growth in male weanling rats kept on a constant 12‐hour day of artificial light and rats kept in the natural lighting conditions of late autumn.
In vitro fertilization of rabbit ova
Authors: Brackett Benjamin G. , Williams William L. 
Published: June 2005

AbstractA repeatable procedure for in vitro fertilization of rabbit ova in which the percentage of ova fertilized is consistently high has been developed. When ova were recovered and subsequently incubated in vitro with capacitated spermatozoa at 37° or 39°C levels of ova fertilized were 15, 24 and 28% when 73–78%, 83%, and 90% relative humidities, respectively, were maintained. Twenty‐one per cent of all ova in these experiments were fertilized. When the ova were recovered at 30–39°C and subsequently incubated at 37° or 39°C with capacitated spermatozoa under paraffin oil only 19% of the ova were fertilized. However, when ova were recovered and subsequently incubated with capacitated spermatozoa and fluids from the female tract all under paraffin oil at 39°C with 96–97% relative humidity levels of ova fertilized were 30, 32 and 73% when stored oviduct fluid, stored uterine fluid, and fresh uterine fluid, respectively, were included in the media. Thirty‐seven per cent of all ova incubated with capacitated spermatozoa under paraffin oil were fertilized. This system with the inclusion of fresh uterine fluid in the medium yields the highest percentage of fertilization with greater consistency than any other system for in vitro fertilization of rabbit ova ever reported.
In vitro studies on 35S‐sulfate incorporation into the acid mucopolysaccharides of chick embryo cardiac jelly
Authors: Gessner Ira H. , Boström Harry 
Published: June 2005

AbstractAn experimental model has been devised for the study of radioactive sulfate incorporation into the cardiac jelly of the isolated stage 18–19 (three‐day) chick embryo heart. Isotope incorporation was found to be optimal in an incubation medium containing glucose, but containing no added unlabeled sulfate. The rate of isotope uptake demonstrated a slight lag during the first 5 to 10 minutes followed by a linear incorporation of at least four hours duration. It is believed that 35S‐sulfate incorporation into the hearts reflects sulfated acid mucopolysaccharide synthesis, and that this system will therefore be useful in studying the significance of this group of compounds in the cardiac jelly.Radioactive sulfate incorporation per unit weight has been found to be inversely proportional to heart weight (i.e., embryo age) over the span of development from stage 14 to stage 24. This probably reflects the fact that cardiac jelly makes up proportionately a greater part of the younger hearts.Sodium salicylate has been shown to inhibit 35S‐sulfate incorporation in this system, in direct relation to its concentration in the incubation medium. This is given as one example of the type of investigation to which this system is adaptable.
Acid mucopolysaccharide content of the cardiac jelly of the chick embryo
Authors: Gessner Ira H. , Lorincz Andrew E. , Boström Harry 
Published: June 2005

AbstractInvestigations of the stage 16 to 19 chick embryo have been performed specifically in relation to the composition of cardiac jelly. Biochemical analysis has demonstrated the presence of a non‐dialyzable sulfated mucopolysaccharide, containing hexosamine and uronic acid. This material can be complexed with cetylpyridinium chloride, and then exhibits differential salt solubility in accordance with known characteristics of acid mucopolysaccharides, suggesting that the chondroitin sulfates and heparin‐like compounds are the major sulfated components. Histochemical and 35S‐sulfate incorporation studies also support the interpretation that cardiac jelly contains a significant amount of sulfated acid mucopolysaccharide.
Vitally stained kappa in Paramecium aurelia
Authors: Mueller Jo Anne 
Published: June 2005

AbstractPurified kappa particles stained with methylene blue were placed into fluid containing paramecia. The vitally stained kappa quickly aggregated in food vacuoles of both sensitive and killer animals. A few filamentous projections were observed protruding into the cytoplasm from vacuoles containing kappa. Occasionally food vacuoles packed with stained particles would disrupt and the contents would disperse throughout the cytoplasm. Paramecia with stained kappa in their food vacuoles were disrupted and the vacuolar contents examined. Virtually all of the kappa from the vacuoles were N particles. Among the thousands of particles observed, only a few B particles were detected.
The duodenal progenitor population. III. The progenitor cell cycle of principal, goblet and paneth cells
Authors: Thrasher J. D. , Greulich R. C. 
Published: June 2005

AbstractThe duodenal progenitor population has been investigated with tritium thymidine (H3‐T) and autoradiography in male Swiss albino mice to characterize the role that individual cell types (principal, goblet, and Paneth) have in the proliferative activity of the duodenal crypt of Lieberkühn.Incorporation of H3‐T into newly synthesized DNA of all three cell types was observed by one‐half after injection of the isotope. Labeled principal and goblet cells were distributed from the first cell of the cryptal mouth to the last cell at the cryptal base. The majority of labeled cells was found in the central region of the crypt Labeled Paneth cells were restricted to the last four cells at the cryptal base.Analysis of the percentage of labeled metaphase and mitotic figures after H3‐T administration showed that the progenitor cycle duration of principal and goblet cells was about 15 hours, while that of Paneth cells was approximately 80 hours. The mean S‐phase duration was 7.4, 7.4 and 8.7 hours for principal, goblet, and Paneth cells, respectively. Thus, the G1 portion of the cell cycle was considerably longer for Paneth cells, while all phases of the progenitor cycle were of the same duration for principal and goblet cells.It appears from the data that the three cell types of the adult duodenal crypt comprise independent populations capable of self‐renewal. Our observations also suggest the existence of causal relationships between the positioning of the proliferative cells types in the duodenal microenvironment and their respective cycle durations.
In vivo culture of Drosophila melanogaster embryos containing the notch deficiencies Df(1)N8 and Df(1)N264‐40
Authors: McCrady Edward 
Published: June 2005

AbstractMale Drosophila melanogaster embryos inheriting deficiencies of the Notch series on the X‐chromosome fail to hatch from the egg, and are characterized in part by almost complete lack of differentiation of the mesoderm. In order to determine the developmental capacities of these tissues, male embryos containing N8 and N264‐40 deficiencies were cultured in vivo in the hemocoeles of wild‐type D. melanogaster larvae and adults. After periods of five and 12 days, the Notch embryos were compared with similarly cultured wild‐type control embryos. The deficient embryos of both types revealed considerable growth. The mesodermal derivatives muscle, fat, and gonad sheath were well differentiated. In every case, embryos of the short deficiency, N264‐40, grew to a greater size than did those of the much longer deficiency, N8. They generally did not exceed the size attained by normal embryos cultured for the same length of time. The growth of transplants in larval hosts always exceeded that seen in adult hosts in the same period of time. Neither of the types of deficient embryos was able to molt in either type of host, although control embryos always molted in larval hosts. The results indicate that the mesodermal tissues of Notch embryos are capable of further differentiation than they are able to exhibit in their own environment, and that the genetic materal within the extent of the N8 deficiency may be involved in their capacity to grow in culture.
Synchronization of Oral Primordia in Stentor coeruleus
Authors: Tartar Vance 
Published: June 2005

AbstractBy grafting and other micrurgical operations, cells and cell‐systems bearing two oral regeneration primordia initially in different phases of development can be produced. There is a strong tendency for the two anlagen to synchronize their developments and complete the later stages of oral differentiation together. The minority of cases, which failed to synchronize the developing primordia, indicated the limits of this coordination and always revealed prominent interaction between the graft components. A simple substrate hypothesis will probably not explain the results. Conclusions are that the oral primordium, once initiated, does not develop autonomously at its own intrinsic rate, and that a cell or fusion of cells performing the same process (elaboration of feeding organelles) in two different places within the system, strongly tends not to do so out of phase but synchronously.
An ultrastructural study of the effects of aeration and physical activity on aging in Tetrahymena pyriformis
Authors: Elliott Alfred M. , Travis David M. , Work Janis A. 
Published: June 2005

AbstractThe ultrastructure of T. pyriformis, strain E, is markedly influenced by the physical conditions of the medium during the growth cycle. Logarithmic growth cells contain a minimal number of mitochondria which are peripherally distributed. Rough endoplasmic reticulum (RER) is abundant and numerous primary lysosomes are scattered throughout the cytoplasm. Lipid droplets are sparse. This situation is unchanged in quiet culture flasks or those that are aerated and/or stirred. When cells enter stationary growth the physical treatment of the medium has profound effects on the cytoarchitecture. In quiet flasks the mitochondria have increased several times over that in young cultures and they are randomly distributed. Lipid droplets are abundant. Very little RER can be seen and primary lysosomes are scarce. A few autophagic vacuoles appear at this phase of growth. When the culture medium has been stirred throughout the growth cycle the ciliates appear quite different. No lipid droplets are formed; the mitochondria are few and peripherally distributed as in young cells. Primary lysosomes and RER are scarce. An occasional autophagic vacuole is observed. Aeration of the medium does not alter this cytoarchitecture. Physical activity of the cells seems to influence the distribution, number, and kinds of particulates. These observations suggest that certain metabolic processes as reflected by ultrastructure are dependent on the physical activity of the ciliates during the growth cycle.
The role of the cellular envelope in the morphogenetic movements of teleost embryos
Authors: Ballard William W. 
Published: June 2005

AbstractNile blue sulfate solutions can be applied to teleost blastoderms in dosages sufficient to stain only the cellular envelope, or to penetrate uniformly from the surface to desired depths among the interior cells. Surface cells, if overstained, break loose from the cellular envelope and migrate to the interior, with subsequent failure of epiboly and differentiation. Less dosage slows down epiboly but does not disrupt organogenesis. The cellular envelope does not contribute any substantial number of cells to the terminal node or any at all to the inner germ ring. The hypoblast is not invaginated from it, nor does it contribute to the notochord, the mesoderm, or the endoderm sheet. Its fate is exclusively epidermal, and it is at all times separable from the inner blastomeres and embryonic tissues. Previously published “fate maps” of the teleost blastodisc must be understood as relating to the internal cells, not the cellular envelope. No conclusive evidence yet exists that the morphogenetic movements of teleosts include either an invagination or an inturning movement, at or inside the blastodisc rim.
Origin of the hypoblast in Salmo. II. Outward movement of deep central cells
Authors: Ballard William W. 
Published: June 2005

AbstractVital dye carriers implanted under the blastodisc and chalk markers injected among the blastomeres provide a new interpretation of the origin of the hypoblast in teleost embryos. This first inner layer of cells is formed along the sides of the embryonic area and around the germ ring, not by invagination from the surface, or by wheeling in of deeper cells, or by delamination at the blastodisc rim, but by the migration outward of deep central cells. The layering is interpreted as the effect of a shear between superficial cells in pure epibolic motion and deeper cells which are at the same time undergoing convergent movement toward the axis. The whole blastodisc could be stained to controllable depths by suitable exposure to vital dye solutions. Subsequent location of the colored cells indicates that at the late “pregastrula” stage the prospective CNS cells overlap those which will become the first 10 pairs of somites, and all the prospective somite material overlaps prospective notochord and endoderm. A teleost pregastrular fate map thus cannot be a surface map as in amphibia. The rim of the teleost blastodisc and the amphibian blastopore carry out totally different functions.
Reversible delay of normal development of frog embryos by inhibition of DNA synthesis
Authors: Flickinger R. A. 
Published: June 2005

AbstractDemembranated gastrulae that had been cultured in 0.05% cytosine arabinoside for a day and subsequently cultured in a saline medium, experienced a delay (1–2 days) in the time at which flexure of the tail‐buds first occurred. Histological sections showed these embryos to be essentially normal. Isotopic experiments revealed that cytosine arabinoside inhibited DNA synthesis, but stimulated the incorporation of C14‐uridine into RNA. There was a slight inhibition of protein synthesis. The results suggest that the reversible delay in normal development during gastrulation is primarily due to the inhibition of DNA synthesis and cell division.
Histochemical localization of acid phosphatase in the Ovary of Gerris remigis Say (Hemiptera)
Authors: Cone M. Virginia , Eschenberg Kathryn M. 
Published: June 2005

AbstractThe localization of acid phosphatase in the telotrophic ovary of the water strider, Gerris remigis, has been studied by light microscopy, utilizing a simultaneous coupling azo dye technique on frozen sections. The enzyme is demonstrable in the cytoplasm of advanced nurse cells, and to a variable degree in the trophic core. Reactivity is also distributed throughout the cytoplasm of young (germarial) oocytes. As oocytes enlarge and pass into the vitellarium, reactivity becomes confined to a peripheral band, which widens and becomes associated with a peripheral accumulation of preyolk bodies. This reactivity disappears from the ooplasm before vitellogenesis is entirely completed. Oocytes which undergo degeneration before completing maturation display large, internal, phosphatase‐reactive areas.Acid phosphatase is first demonstrable in follicle cells at the onset of vitellogenesis. Variations in its intensity and intracellular localization are in conformity with previous suggestions in the literature that follicle cells are implicated in vitellogenesis and in subsequent chorion elaboration. Following ovulation, the follicle cells become intensely reactive and as they degenerate, some of this reactive material is expelled from the ovary through the follicle cell basal surfaces. Reactive residues accumulate in the yellow body at the base of the ovary. Thus the enzyme localization is correlated with physiological autolysis in nurse cells and post‐ovulatory follicle cells and with pathological autolysis in oocytes. Its localization in normally developing oocytes and follicle cells suggests involvement in the process of vitellogenesis and chorion formation as well.
Atypical transovarial transmission of sex ratio spirochetes by Drosophila robusta sturtevant
Authors: Williamson David L. 
Published: June 2005

AbstractThe pattern of transmission of Sex Ratio spirochetes to the progeny of Drosophila robusta females that had been injected with spirochete‐laden hemolymph was studied. Males appeared with about the same low frequencies in all the broods, but spirochetes were transmitted in high frequencies only to the early brood progeny, the transmission to later progeny being greatly reduced. This pattern is in striking contrast to that observed in D. melanogaster and D. pseudoobscura females in which males appear in nearly equal numbers along with females in the early broods, when the frequency of spirochete transmission is low, but disappear completely from the later broods, when all the females possess a dense population of spirochetes in their hemolymph.The transmission pattern in D. robusta supports the idea of a separation between the spirochete itself and the factor responsible for male lethality.
On the application of immunological techniques in geographic group studies of Atlantic sea herring, Clupea harengus. I. Neutralization of immune precipitins as an aid to herring serum analysis by immunoelectrophoresis
Authors: Di Capua Richard A. 
Published: June 2005

AbstractThe sera of Atlantic sea herring, collected from 13 contiguous oceanic locations, were analyzed by immunoelectrophoresis for precipitinogen differences. An immune serum (rabbit) against the sera from each location was required. Electro‐phoretic characteristics suitable for identifying the geographic origins of herring sera were not detected. Immune serum aliquots were therefore individually neutralized with undiluted or one of a series of dilutions of herring serum from each geographic location prior to analysis. The use of undiluted serum resulted in complete precipitin neutralization regardless of its origin. Equivalent dilutions of each serum resulted in varying degrees of precipitin neutralization. This capacity of origin‐separate precipitinogens appears to be related to the geographical distance separating the origins of immunizing and neutralizing sera, i.e., the greater the distance the higher the concentration necessary for equivalent neutralization. Sera of unknown origins can be related to sera from specific origins by comparison at equivalent dilutions for equivalent precipitin neutralization, providing they originate from the overall area sampled. Immunoelectrophoretic results are consistent regardless of sex, number of individuals contributing to the sample or the collection date. Herring precipitinogens are identified by comparison with the well‐established mobilities of human precipitinogens and are discussed based on the frequency with which they are associated with geographic group differences.
Limb regeneration and nerve fiber number in Rana sylvatica and Xenopus laevis
Authors: Rzehak Karol , Singer Marcus 
Published: June 2005

AbstractAdult Rana sylvatica does not regrow an amputated forelimb whereas Xenopus laevis does. This difference in regenerative behavior has been analyzed in terms of the number of nerve fibers available at the amputation surface because previous studies have shown that nerve fibers must satisfy a quantitative threshold in order that regeneration occur. Our results show that Xenopus has more fibers per unit area than Rana. However, the value for both is far below that of Triturus and, indeed, even lower than that of the mouse. The relative scarcity of fibers in the anuran limb thus brings into question the direct relation previously drawn between nerve number and regenerative capacity in vertebrates. However, anuran nerve fibers are much larger fibers than those of other vertebrates; and, indeed, those of Xenopus surpass in size the fibers of the vertebrates we have investigated. Initial studies show that if the size of fibers is taken into account and the inneryation is expressed as amount of neuroplasm available at the amputation surface rather than as the number of fibers, the limb of Xenopus is then as richly innervated as the limb of Triturus whereas that of Rana contains much less nervous substance.
Hypophysial cysts in a teleost fish
Authors: Schreibman Martin P. 
Published: June 2005

AbstractIn an investigation of six stocks of platyfish (Xiphophorus maculatus) in the Genetics Laboratory of the New York Zoological Society, only one exhibited pituitary cysts. Cysts were discovered in 58 of 76 (76%) of the fish of the Gp (Grijalva) strain that were one month or older. This strain originated from the Rio Grijalva, Mexico, and has been inbred for many generations in this laboratory.Cysts were first seen shortly after birth and they increased in size with age. This enlargement results from an increase in the number of typical goblet cells that form the wall of the cyst and by an accumulation of their PAS — positive secretion. More than one cyst rarely occurs in a gland. Cysts may be found in all portions of the adenohypophysis, most frequently in the meso‐adenohypophysis, but they never occur in the neurohypophysis. Hypophysial cysts were not found in Gp embryos, in offspring of crosses between Gp females and males from other platyfish stocks and in wild‐caught fish from the Rio Grijalva. Fish of the Gp strain that showed abnormal gonadal development always possessed a pituitary cyst, but not all fish with pituitary cysts were hypogonadal.The information presented points to the fact that the origin of cysts has a genetic basis and perhaps arose as a result of inbreeding. It is suggested that cysts result when cells of the adenohypophysial anlage fail to differentiate into pituitary cells but become goblet cells instead.
Rejection of skin homografts in larvae of Rana pipiens
Authors: Bovbjerg Ann M. 
Published: June 2005

AbstractLarvae of the leopard frog, Rana pipiens, regularly reject skin homo‐grafts. Grafts from sibling larvae show initial signs of necrosis later than grafts from non‐siblings; grafts between very young feeding larvae also show initial necrosis later than those between older larvae. Homograft rejection pattern is essentially the same in larvae of stage IV and older, in hypophysectomized larvae, and in larvae immersed in thyroxine for two weeks after grafting. Second grafts from the same donor are necrotic 4 to 5 days before first grafts are. The conclusion is drawn that destruction of skin homografts in frog larvae is independent of metamorphic phenomena, and is an immunologic reaction, possibly involving the thymus gland. The weakened response of very young larvae may reflect an immunologic mechanism that is not yet mature.