bluuebunny/crossref_metadata_2025_split huggingface dataset:
Galapagos iguanas: Amblyrhynchus and Conolophus serum protein relationships
Authors: Higgins Paul J. , Rand Charles S. , Haynes Janet‐L. 
Published: June 2005

AbstractThe serum proteins of two genera of Galapagos iguanas were studied by means of immunochemical and electrophoretic methods. The albumin‐like fraction of the serum of the Galapagos land iguana, genus Conolophus, demonstrated greater anodal mobility than the albumin of Amblyrhynchus, the Galapagos marine iguana. The marine reptile was shown to possess four antigenic serum components not found in the land reptile. Double‐diffusion analysis, using rabbit antiserum to the serum of Amblyrhynchus cristatus (Santa Cruz Island), indicated taht the antigenic profile of the Santa Cruz, Hood, Tower, Albemarle and James Island populations of Amblyrhynchus were identical when the eliciting immunogen is the serum of the Santa Cruz marine iguana.
Physiological studies of conducting systems in the colonial hydroid Hydractinia echinata. I. Polyp specialization
Authors: Stokes Darrell R. 
Published: June 2005

AbstractElectrical activity generated by electrical stimuli has been recorded through suction electrodes placed on gastrozooid and dactylozooid polyps of the colonial hydroid, Hydractinia echinata Flemming. The polymorphism so characteristic of a Hydractinia colony extends to the physiological machinery controlling the behavior of the different polyp types. Contraction of gastrozooid polyps, where the muscle elements are uniformly distributed within the epidermis, is correlated to an electrical event termed the symmetrical contraction potential (SCP). The SCP is conducted about 4.4 cm/sec. Two kinds of electrical activity are correlated to distinct behavioral events of the specialized asymmetrically coiled dactylozooid polyps: (1) Dactylozooid coiling potentials (DCPs) are conducted at about 4.6 cm/sec and are correlated with contraction of a thin band of muscles on the concave side resulting in asymmetrical contraction and a marked coiling of the polyp. (2) Dactylozooid lashing potentials (DLPs) are conducted at about 9.1 cm/sec and have a threshold 50 per cent or more higher than DCPs. DLPs are correlated with contraction of well‐developed muscles on the convex side resulting in a rapid uncoiling or “lashing” of the dactylozooid polyp. Dactylozooid coiling is correlated to an incremental spread of conduction within the colony whereas lashing occurs during colony‐wide through‐conducted excitation. Very small electrical spikes (50–200 μV amplitude) have been recorded from both gastrozooids and dactylozooids. These tiny potentials (TPs) are conducted at 15–21 cm/sec, have a threshold below that of the DCPs and SCPs, and are of unknown behavioral significance. On the basis of the characteristics of the electrical events, the differences in threshold, conduction velocity, and related spread of excitation, it is proposed that these three potentials represent activity within separate conducting systems — an incrementing conducting system (ICS), a through conducting system (TS), and a tiny potential system (TPS). Physiological and microscopical evidence suggest a nerve net origin for the ICS, and epithelial conduction for the TS.
In vitro maturation of mouse oocytes isolated from late, middle, and pre‐antral graafian follicles
Authors: Erickson Gregory F. , Sorensen Ralph A. 
Published: June 2005

AbstractOocytes were dissected from late, middle, and pre‐antral Graafian follicles from sexually mature mice (6–8 weeks old), cultured in vitro in a chemically defined medium for 18 hours, and scored for meiotic maturation. Between 83–91% of the oocytes removed from antral follicles (300–600 μm in diameter) progressed to either metaphase I or metaphase II. In marked contrast, 98% of the oocytes removed from pre‐antral follicles (100–150 μm in diameter) failed to resume meiosis and remained in the germinal vesicle stage. These and other data suggest there is a close correlation between the capacity of the mouse oocyte to resume meiosis and the appearance of the antrum in the developing follicle.
Blood glucose regulation in larval and adult salamanders (Ambystoma tigrinum)
Authors: Bartell Marvin Henry , Frye B. E. 
Published: June 2005

AbstractBlood glucose in Ambystoma tigrinum is regulated at a lower level in larval (18.4 ± 0.7 mg%) than in adult (27.8 ± 0.8 mg%) animals. The difference is observed at all seasons, and is not related to differences in size, diet or sexual maturity. A difference in the blood glucose regulating mechanism in pre‐ and post‐metamorphic animals is further shown by three other observations: (1) larvae are more insulin sensitive than adults; (2) larvae have a slightly greater glucose tolerance than adults; and (3) pancreatectomy causes a more severe hyperglycemia in adults than in larvae.The best hypothesis to account for all of these observations is that an increase in the amount and/or activity of insulin antagonistic hormones occurs at metamorphosis.
Collagen synthesis in the regenerating forelimb of the adult newt, Diemictylus viridescens
Authors: Johnson Martha C. , Schmidt Anthony J. 
Published: June 2005

AbstractThe regenerating and stump tissues of amputated forelimbs of the adult newt, Diemictylus viridescens, were analyzed for collagen content and synthesis. Collagen soluble and insoluble in 0.45 M NaCl was assayed by (1) spectrophotometric determination of hydroxyproline, (2) radiotracer determination of 14C‐proline incorporation, and (3) radiochromatographic analysis of the 14C‐proline/14C‐hydroxyproline ratio in the two collagen fractions.The results obtained reveal that there is significantly less saline insoluble as well as soluble collagen in the regenerating limb tissues than in the basal stump of the amputee, though a soluble fraction is demonstrable throughout the course of regeneration. By ninety days after amputation, there is a significant increase in the insoluble collagen fraction in the regenerating limb.The soluble collagen fractions assayed in the regenerating tissues are newly synthesized protein, and this synthetic activity appears to be greatest during the paddle and early digitiform stages of regeneration. The soluble collagen extracted from regenerates appears to be less completely hydroxylated with respect to hydroxyproline content than obtains in corresponding fractions from limb stump and control limb tissues.
Cell division and determination of the dorsal lip in Rana pipiens embryos
Authors: Grant Philip , Youngdahl Pamela 
Published: June 2005

AbstractUV irradiation of vegetal halves of fertilized eggs of Rana pipiens delays the onset of gastrulation and inhibits neural induction. To test a hypothesis that delay in dorsal lip formation results from inhibition of mitotic activity in vegetal halves we examined the incorporation of thymidine H3 into DNA of whole and half irradiated embryos. Tritium labeled thymidine was injected into control and irradiated eggs and at six hour intervals samples were taken until controls had reached mid gastrula stages. Whole embryos as well as animal and vegetal halves were compared for levels of incorporation into DNA. No significant differences were seen between control and irradiated whole or animal half embryos but irradiated vegetal halves displayed a 15–20% reduction in incorporation into DNA at 18 and 24 hours. This result is consistent with (but by no means proves) the hypothesis that UV inducedgastrulation delay results from inhibition of cell division of vegetal half cells.
Localization of rhodomelanochrome in melanosomes of leaf frogs
Authors: Bagnara Joseph T. , Ferris Wayne 
Published: June 2005

AbstractRhodomelanochrome, a new pigment extracted from the skin of leaf frogs is localized in the fibrous portion of the large melanosome typical of these frogs. Skin extracted with NaOH contains melanosomes possessing a diminished fibrous component and melanophores in thin sections of skin treated with NaOH are filled with melanosomes that lack large areas of the fibrous zone. The appearance of the electron‐dense core of the melanosome of untreated skin is unchanged and it is suggested that the leaf frog melanosome is composed of an inner kernel of eumelanin and an outer fibrous component of rhodomelanochrome.
Massive cytoplasmic transfers between early blastomeres of Rana pipiens eggs
Authors: Ansevin Krystyna D. , Williams Barbara J. 
Published: June 2005

AbstractA technique for injecting large amounts of cytoplasm into early blastomeres of frog eggs is reported. It has been possible to replace part of the cytoplasm of animal blastomeres at the 8‐cell stage with injected cytoplasm, some of which was also included in the upper region of the corresponding cell in the vegetal hemisphere. When the injected cytoplasm matched the stage and type of the cytoplasm at the site of injection, the majority of the recipient embryos developed into normal larvae. If it matched the stage, but not the type, the majority of the eggs developed abnormally. The experiments also indicated a relationship between the stage of injected cytoplasm (4‐64+ cells) and the frequency and severity of abnormalities.
Cell surface structure of rodent sperm heads
Authors: Phillips David M. 
Published: June 2005

AbstractReplicas of critical point dried rodent sperm were examined by transmission electron microscopy. The surface of rat sperm heads appeared to be coated with regularly spaced 90A lamellar material. The plasma membrane overlying the acrosomal region of guinea pig spermatozoa displayed a regular scalloped array of lamellar structures. In replicas, the surface of Chinese hamster spermatozoa appeared coated by an array of small tubules and vesicles in the region overlying the acrosome. It was possible to obtain replicas of the outer acrosomal membrane by removing the plasma membrane of mouse spermatozoa by brief treatment with Hank's balanced salt solution containing 0.2–0.5% MgCl2. Replicas of the surface of the outer acrosomal membrane reveal evenly spaced, hexagonally‐packed 90A particles similar to those which have been observed by other workers in replicas of freeze fractured outer acrosomal membranes. The finding of hexagonally arranged structures on the surface of the outer acrosomal membrane which appear very similar to those which have been observed in the plane of the membrane suggests that protein molecules in the plane of the membrane may protrude through or in some other manner distort the membrane surface. The post‐acrosomal region of mouse sperm displays parallel lamellae with 100A spacing. If surface changes occur on sperm heads during maturation or capacitation, it should be possible to detect them with this technique.
An effect of accumulated matrix on sulfation among cells in a cartilage colony: An autoradiographic study
Authors: Solursh Michael , Karp Gerald C. 
Published: June 2005

AbstractIn this report an autoradiographic approach is used to compare synthetic activities of cells within differentiated cartilage colonies. While amino acid incorporation is uniform throughout the colony, H3‐uridine is incorporated more actively by cells having little matrix, cells which are typically in the peripheral regions of a colony. On the other hand S35O4 is incorporated most actively by cells in the colony centers. This difference in sulfation appears to occur independently of the mitotic state of the cells, since it is apparent in both growing and near‐stationary cultures. Instead, there is a correlation between the accumulation of extracellular matrix and more active levels of sulfation. In support of the idea that matrix creates a microenvironment more favorable to chondrogenesis is the observation that a brief treatment with hyaluronidase, which removes about 60% of the S35O4 from prelabeled cultures, depresses sulfation, as determined both autoradiographically and biochemically by the isolation of labeled glycosaminoglycans. The possible role of extracellular matrices in altering the expression of differentiated functions by creating a more favorable microenvironment is considered.
Exogenous and endogenous control of the annual reproductive cycle in the male golden hamster: Participation of the pineal gland
Authors: Reiter Russel J. 
Published: June 2005

AbstractTestes and accessory sex organs (seminal vesicles and coagulating glands) of hamsters exposed to natural lighting (NL) conditions beginning September 22 underwent complete degeneration by October 31. The following February the testes began to regrow with the regeneration being complete by mid to late March. Associated with the atrophic response of the testes during the winter months was a consistent depression in pituitary prolactin and an inconsistent decrease in pituitary luteinizing hormone levels. If hamsters are pinealectomized prior to their exposure to NL, the sexual organs do not atrophy and the pituitary hormone levels do not drop. Moving hamsters from NL to the long daily photoperiods (light:dark cycles of 14 hrs light and 10 hrs darkness— LD 14:10) of the laboratory near mid winter is followed by regrowth of the gonads and accessory glands. Regeneration of the reproductive system in the spring is not a function of increasing photoperiodic length since if animals are completely deprived of light (by blinding) in February, the gonads still regenerate. When hamsters are exposed to LD 14:10 cycles during the subsequent summer, the return to NL on September 22 is followed by a second involution of the reproductive system. However, if the period of LD 14:10 (the simulated summer) is shortened by ten weeks, the second return to NL does not initiate involution of the reproductive system. During the simulated summer complete light deprivation by blinding is incapable of forcing atrophy of the sexual organs.
Localization of prostaglandin on the plasmalemma of rabbit sperm
Authors: Bartoszewicz Wladyslaw , Dandekar Pramila , Glass Robert H. , Gordon Mildred 
Published: June 2005

AbstractProstaglandin and prostaglandin receptors were localized on unwashed ejaculate rabbit sperm utilizing ferritin conjugated antibody to prostaglandin. Reaction was obtained over the acrosomal portion of the plasma membrane, with a greater aggregation over the apex of the head. The remainder of the head plasmalemma and flagellum showed no deposits of reaction product. The reaction did not occur if the sperm were washed prior to incubation with the labelled antisera. However enhanced binding of ferritin was demonstrated if washed sperm were pre‐incubated in PGE1.No reaction was seen in similar studies with human sperm.
Neurosecretory stimulation of galactogen synthesis within the Helix pomatia albumen gland during organ culture
Authors: Goudsmit Esther M. 
Published: June 2005

AbstractThe albumen gland portion of the female reproductive tract in pulmonate gastropods produces two metabolically allied polysaccharides, galactogen and glycogen. Galactogen accumulates in preparation for summer egg‐laying, glycogen in preparation for winter hibernation. Synthesis of each polysaccharide may be under neurohormonal control, therefore an organ culture bioassay for such neurosecretory influences was devised.This publication reports: (1) the composition of a chemically defined medium which will sustain both the albumen gland and brain of Helix pomatia in organ culture; (2) a method for the separation of galactogen from glycogen in aqueous solution: glycogen is co‐precipitated with concanavalin‐A while galactogen remains in solution; and (3) activation of galactogen synthesis within albumen gland explants of a hibernating Helix, when this gland is cultured in the presence of a brain taken from a reproductively active snail.
The differential effects of prenatal and postnatal audiogenic stress on fluctuating dental asymmetry
Authors: Siegel Michael I. , Doyle William J. 
Published: June 2005

AbstractAudiogenic stress has been shown to have an effect on the development of molar teeth. The present study demonstrates the relative contribution of prenatal and postnatal stress components to increases in fluctuating dental asymmetry in the laboratory rat. It is shown that there is a limit to the amount of change which can be environmentally induced and that if this limit is reached with prenatal stress, postnatal stress will have no significant effect. Audiogenic stress is shown to effect differentially mandibular and maxillary first molars. Length is stable for the maxillary dentition and width is stable in the mandibular molars.
The role of a normal lens in Wolffian lens regeneration
Authors: Williams Leah A. , Higginbotham Linda T. 
Published: June 2005

AbstractThe mid‐ventral third of the iris was excised from 61 adult Notophthalmus viridescens hosts, and the mid‐dorsal third of the iris from donor eyes was implanted in its place. After the iris healed and the host lens was removed, two lens regenerates developed, one from the host and one from the transplanted iris. The host regenerate was removed 53–91 days after the first lentectomy. Animals were sacrificed 1–40 days after the second lentectomy. A lens developed from the host dorsal iris in the presence of a normal regenerated lens in 75% of the cases. A large space was present between the transplant derived lens and host iris for approximately 20 days after the removal of the host lens at lentectomy 2. Stimulatory factor(s) from the neural retina could reach the competent iris through this space, inducing it to regenerate a lens. Therefore, contact between the normal lens and iris probably acts to prevent lens regeneration.In other experiments, variable amounts of neural retina from either adult or larval donors were implanted into the anterior chamber of adult newt eyes in which the lens, iris and neural retina remained in their normal relationships. Implants also contained dorsal iris, ventral iris, or no iris at all. Competent iris tissue, stimulated by the implanted retina, showed only early stages of lens regeneration, but larval retina effected a greater response than adult retina. This limited response may result from the small amount of retina in the implant, a deficiency in retinal stimulus, or a competition for the retinal factor(s) by competent iris tissues.
The effects of castration on song development in zebra finches (Poephila guttata)
Authors: Arnold Arthur P. 
Published: June 2005

AbstractIt has been suggested that the learning processes which occur during the critical period for bird song development are dependent on androgens. Castration of male zebra finches (Poephila guttata, Estrildidae) at ages 9–17 days did not prevent song development, and normal learning occurred after the time of castration. Thus the learning processes of song development occur in the absence of gonadal androgens. Castrates tended to develop song more slowly than normals, which is potentially attributable to a decreased rate of singing in the castrates, or to a direct effect of androgen on the learning processes.
The quantitative role of hemocyanin in aerobic respiration of limulus polyphemus
Authors: Mangum C. P. , Freadman M. A. , Johansen K. 
Published: June 2005

AbstractMeasurements of the total oxygen content of post‐ and prebranchial blood in Limulus polyphemus indicate that hemocyanin transports less than half of the oxygen consumed in water but almost 90% in air. Half of the increase in hemocyanin function during air exposure is due to the occurrence of a reverse Bohr effect.
The effects of castration and androgen replacement on song, courtship, and aggression in zebra finches (Poephila guttata)
Authors: Arnold Arthur P. 
Published: June 2005

AbstractCastration of adult male zebra finches (Poephila guttata, Estrildidae) reduces their singing rate and the tempo of song, but castrates continue to sing song identical in form to preoperative song. Injection or implantation of testosterone propionate (TP) but not of vehicle alone reverses the changes produced by castration. Castration or partial castration also reduces the frequency of courtship, copulation, and aggression. Androgen (TP) replacement reverses these changes, but control injections do not. The persistence of song after castration contrasts with the abolition of song by castration in other birds, and this may be related to the natural history of zebra finches.
Panting thresholds of lizards. IV. The effect of dehydration on the panting threshold of Amphibolurus barbatus and Amphibolurus muricatus
Authors: Parmenter C. J. , Heatwole Harold 
Published: June 2005

AbstractAmphibolurus barbatus which occupies arid and mesic habitats elevates its panting threshold with increasing loss of body water, thereby minimizing water loss at the expense of thermoregulatory effectiveness. Change in panting threshold is greatest up to losses of body water of 6–8% of hydrated weight, after which adjustment of the threshold is of lesser magnitude. Amphibolurus muricatus, a species restricted to the more mesic regions of Australia, does not show any change of panting threshold with progressive dehydration.
The immune response of the teleost, Tilapia mossambica to soluble and cellular antigens
Authors: Sailendri K. , Muthukkaruppan Vr. 
Published: June 2005

AbstractThe immune response of Tilapia mossambica to bovine serum albumin (BSA) and sheep red blood cells (SRBC) was characterized in detail in terms of the appearance of hemolysin plaque‐forming cells and circulating antibodies at 30°C.Plaque‐forming cells (PFC) were detected in the spleen, head‐kidney and thymus of immunized fish and the maximum number was observed in these organs on the fifth day after immunization with SRBC. Peak circulating antibody response occurred on day 8 for SRBC and on day 11 for BSA. Following the second injection of the same antigen, a specific anamnestic response was observed with increased production of PFC and serum antibody.No cross reactivity was found when anti‐SRBC antibody was tested with rat erythrocytes. Tests with 2‐mercaptoethanol showed that all of the agglutinating antibody produced after both the first and second injection was mercaptoethanol sensitive.Analysis of histological and smear preparations revealed that there were consistent cellular changes occurring in the spleen as well as the head‐kidney due to immunization.
Electron microscopic study of erythrocytes in developing rainbow trout, Salmo gairdnerii irideus, with particular reference to changes in the cell line
Authors: Yamamoto Masamichi , Iuchi Ichiro 
Published: June 2005

AbstractThe fine structure of the first erythroid cells in the embryonic circulation of the rainbow trout and new erythroid cells appearing after hatching was examined by scanning and transmission electron microscopy. The first erythroid cells in the embryos. where circulation has just begun, are very immature in ultrastructural characteristics; they are spherical, relatively large, and contain a large nucleus with diffuse chromatin and numerous free ribosomes mostly occurring as polyribosomes. The cells divide in the circulatory system. As development proceeds, the entire population undergoes a synchronous maturation, i.e., transformation into round and flat discs, progressive heterochromatization, reduction in number of cytoplasmic organelles, especially of ribosomes, and a concomitant increase of hemoglobin content. The fully mature first erythroid cells persist until after hatching and are gradually replaced by a new population of erythroid cells which begin to appear in the circulatory system within a few days after hatching. The new cells are at first small and spherical, and show immature ultrastructural features, but no dividing cells were encountered. The cytological changes accompanying maturation are almost parallel to those seen in the first class of erythroid cells. In the circulatory system of fry, where yolk absorption has just been completed, almost all the erythroid cells are mature. These cells are uniformly flat and elliptical discs. The differences in ribosome numbers in electron micrographs of erythroid cells from different stages of development are also consistent with the existence of two series of erythroid cell maturation in the peripheral blood of the developing rainbow trout.