bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in testicular cholesterol associated with estrogen induced infertility in male mice
Authors: Simmons J. Emmett 
Published: June 2005

AbstractMale mice were injected on the fifth postnatal day with 50 μg of estradiol undecylate and the changes in morphology and testis cholesterol were studied at 10, 20, 40, 60 and 90 days. Such treatment resulted in decresed body weight, atrophic testes and seminal vesicles, adrenal and pituitary hypertrophy, failure of scrotal development with crptorchidism, impaired spermatogenesis, and alopecia. The onset of these changes, however, occurred at different ages. Testicular atrophy was manifest as early as day 20, while seminal vesicle atrophy and adrenal hypertrophy were not apparent until day 40, and a decreased body weight and alopecia were observed by day 60. Pituitary hypertrophy was observed at only day 90.There were no significant differences in total testicualr cholesterol between estrogenized and control mice at ten days. However, at all other stages studied experimental animals had significantly more cholesterol than their oil injected controls. This increase in cholesterol within the testes of estrogenized mice is interpreted as decreased utilization of cholesterol for steroidogenesis. That there was a lack of endogenous androgen in these estrogenized mice as late as 90 days was indicated by atrophic seminal vesicles and the presence of an x‐zone in the adrenal gland.
Effects of the deafferentation of the trigeminal area on the motility of the chick embryo
Authors: Hamburger Viktor , Narayanan C. H. 
Published: June 2005

AbstractThe neural crest and placodal primordia of the trigeminal ganglion were extirpated bilaterally at stages 11–12. Tests of the tactile sensitivity of different head regions showed the absence of responses to stimulation in 31 of 35 deafferented embryos. In a histological study of eight randomly selected experimental embryos small residual ganglia and trigeminal nerves were found; however, they were apparently functionally ineffective. Midbrain and cerebellar defects were found in 60% of the embryos.Periodic motility was recorded mechanically, as in previous studies, in embryos between 9 and 17 days. Random motility up to 15 days was not different in normal and deafferented embryos. This implies that self‐stimulation of the head, for instance, by brushing of legs or wings against the head, or proprioceptive self‐stimulation, play no role in the random motility at least up to 15 days. A decline of spontaneous motility which occurs in normal embryos after 17 days, begins in experimental embryos already at 15 days. This may be due to the absence of sensory input or, at least in the majority of cases, to the above‐metioned brain damage.The operated embryos did not hatch but remained in a position characteristic of the 17‐day stage. The failure to perform the integrated prehatching and hatching behavior may be due to either one of the following causes: (1) Absence of specific sensory information; (2) Absence of non‐specific excitatory stimulation reducing muscle tonus; (3) Transneuronal degeneration in trigeminal medullary or in higher centers; (4) Damage in the midbrain and/or cerebellum.
Ontogeny of the immune response to skin allografts in relation to lymphoid organ development in the amphibian Xenopus laevis Daudin
Authors: Horton John D. 
Published: June 2005

AbstractThe response of larval and adult Xenopus to first set skin allografts was studied by examination at regular intervals of the external appearance of the grafts and of serial sections through the graft region. Operations were performed on all stages of larvae ranging from those with rudimentary to those with mature lymphoid organs. Larvae received single allografts from either larval or adult donors, skin from the latter being a good morphological marker: adults received adult skin only. Control autografts were also applied to both larval and adult toads.All autografts were accepted; no incompatible phenomena were observed. Both adults and larvae, even those operated at the most immature stage of development, were able to repond immunologically to the skin allografts. The response was similar in larval and adult toads and included a lymphocytic invasion of the graft which disappeared when destruction of the graft was near completion. This invasion was correlated with the state of development of the lymphoid organs of the host: if these organs were immature at the time of application of the graft, the invasion was delayed but eventually occurred when the host reached a more advanced larval stage. The capacity to invade a graft with lymphocytes could be correlated with the lymphoid maturation of the thymus.These results support the view that the allotransplantation of tissues in immature amphibian larvae, before acquisition of immunological competence, does not necessarily preculude the possibility of an immune response to the same tissues in more mature larvae.
Chronic allograft rejection in Lumbricus terrestris
Authors: Cooper Edwin L. 
Published: June 2005

AbstractTo determine the capacity of earthworms to reject tissue transplants, first‐set orthotopic allografts of body wall were exchanged between 280 adult Lumbricus terrestris. In addition, 30 worms were autografted as controls. Both auto‐ and allogeneic tissue transplants healed in promptly; autografts survived permanently while allografts showed varying degrees of incompatibility. Intrapopulation allografts in worms from Canada showed 22% permanently surviving transplants while 95% were not destroyed in the Oregon group; the remaining allografts in both groups were completely destroyed after prolonged chronic periods or showed incomplete rejection after observations during eight and one‐half months. No intrapopulation Oregon transplants were rejected completely while only 1% were in the Canadian group. About 5.5% of interpopulation allografts were destroyed on Oregon hosts and 15.3% on Canadian recipients between 38 and 153 days after grafting. Therefore, recognition and rejection of tissue allo‐antigens are characteristic of the primitive immune response of annelid worms.
Terminal respiration in minute mutants of Drosophila
Authors: Farnsworth M. W. , Jozwiak J. 
Published: June 2005

AbstractOxidative phosphorylation was studied in mitochondria isolated from third instar larvae heterozygous for the following Minute mutations: M(2)S‐10, M(2)l2, M(2)l, M(3)Y and M(3)l. The substrates utilized inculded α‐ketoglutarate, pyruvate with malate, succinate, α‐glycerophosphate and ascorbate. Mitochondria from an additional mutant, M(2)z, were also tested for their ability to metabolize α‐glycerophosphate. Abnormalities associated with the cytochrome b‐c site of phosphorylation were evident in all mutant genotypes. Additional lesions at the substrate level and at the DPN‐DPNH site of phosphorylation in the electron transport system were also identified in one or more of the mutants analyzed.
Chronology of spermatogenesis and spermiogenesis in poeciliid fishes
Authors: Defelice Diane A. , Rasch Ellen M. 
Published: June 2005

AbstractAnalysis by autoradiography after a single pulse label with 3H‐thymidine was used to mark the chronology of cell progression through spermatogenesis and spermatid differentiation in the ovoviviparous teleost fish, Poecilia sphenops, the aquarists' “black molly.” A minimum of 21 days was required from initiation of meiotic prophase to the development of mature, aggregated sperm. An additional two weeks elapsed during transport of sperm through testicular ducts, so that shed spermatophores with labeled sperm were found only after 35 or more days following isotope injection. Time estimates for various stages of spermiogenesis were independently confirmed by assessment of the duration of elapsed time using frequency of occurrence of particular stages within the total population of testicular crypts as an index of relative elapsed time.
Effects of mammalian gonadotropins on the ovaries and oviducts of the lizard, Lygosoma laterale
Authors: Jones Richard E. 
Published: June 2005

AbstractFemale Lygosoma laterale with quiescent ovaries and oviducts were treated with 1.0 I.U. of either FSH, LH, FSH plus LH, PMS or HCG daily for 15 days to elucidate their effects on the reproductive tract. FSH increased ovary and oviduct weight and follicle diameter, but its effects were antagonized by LH. Neither HCG nor LH had an effect on ovary weight or follicle diameter, and both only slightly increased oviduct weight. The effects of PMS were similar to those of the FSH‐LH combination, both causing a moderate increase in ovary and oviduct weight and follicle diameter. These results are discussed in relation to the effects of exogenous mammalian gonadotropins in other reptiles and in mammals.
Effect of actinomycin D on antigen synthesis during sea urchin development
Authors: Westin Monica 
Published: June 2005

AbstractEggs and developmental stages of the sea urchin Paracentrotus lividus were incubated with radioactive (14C) amino acids. Incorporation of label into antigen was studied by means of rabbit antisera against sea urchin material. In an attempt to block genetic control of protein synthesis, eggs and embryos were treated with actinomycin D during different periods of development.During normal development the antigen‐labeling pattern, studied by immunoelectrophoresis and autoradiography, remained essentially unchanged until hatching. In the mesenchyme blastula, however, a new labeled antigen was detected, and one which earlier was unlabeled became heavily labeled. As seen in autoradiographs, during the same period, the intensity of labeling of other antigens also changed. When the embryos were exposed to actinomycin D (10–20 μg/ml) from hatching or some hours before, the development stopped at the mesenchyme blastula stage and these embryos never developed the labeling pattern characteristic of normal mesenchyme blastula.The results suggest that in contrast to the early development, gastrulation requires new production of templates. These templates seem to be essential for the changing pattern of antigen‐labeling. It is suggested that alterations in amino acid incorporation into antigens reflect changes in synthesis of proteins necessary for gastrulation.
Amylase variants in Drosophila melanogaster: Linkage studies and characterization of enzyme extracts
Authors: Doane Winifred W. 
Published: June 2005

AbstractThe amylases of D. melanogaster were characterized by several parameters. Starch‐iodine and 3,5‐dinitrosalicylic acid reduction methods were employed to determine activity. Conditions were defined under which activity, in crude aqueous extracts could be restricted to α‐amylase(s) of fly origin. Biochemical properties of the α‐amylases from eleven homozygous Amy strains were found to be very similar in temperature stability, pH optimum, substrate specificity and the effects of various activators and inhibitors. All were activated by chloride ions and showed a pH optimum of about 7.4. Relative efficiencies on several substrates were tested: soluble starch, amylopectin, β‐limit dextrins, glycogen and amylose. EDTA completely inhibited all extracts, presumably by the removal of calcium required for activation. The specific α‐amylase inhibitor from wheat grain also completely inhibited activity, as did reduced glutathione. PCMB had no discernible effects on activity.Eight of the 11 strains tested are known to produce different electrophoretic banding patterns for amylases. The total maximum activity of each strain may also be used to characterize it and, accordingly, three strains with amylases of the same electrophoretic mobility were distinguished by differences in their specific activities. Sexual dimorphism in amylase activity was defined, as well as activity in heterozygotes between strains. Aside from the distinctions between strains already noted, four strains differed in their relative susceptibility to heat and to α‐amylase inhibitor.Linkage experiments indicated that the Amy region lies at 77.3 on the genetic map of the second chromosome and to the right, but near, section 52F on the salivary chromosome map.
Electrophoretic variations of tyrosinase in follicular melanocytes during the hair growth cycle in mice
Authors: Burnett Jean B. , Holstein Thomas J. , Quevedo Walter C. 
Published: June 2005

AbstractMultiple forms of tyrosinase separable by acrylamide‐gel electrophoresis are demonstrable in extracts of hair bulbs prepared on the fifth (anagen IV) through the thirteenth days (anagen VI) of a hair growth cycle induced in C57BL/6J mice by plucking of quiescent hairs. The enzymic bands visualized by incubation of the gels in L‐DOPA have been designated as T1, T2 and T3. Although T1 has been observed through day 19, the T2 and T3 components disappear by day 15 of the hair growth cycle. Tyrosinase activity is not demonstrable in skin extracts prepared during telogen or on days 1–3 post‐plucking (anagen I–III). The slow development of a single DOPA‐melanin band in such samples has been demonstrated to represent non‐specific oxidation by hemoglobin that migrates at a slightly slower rate than the T3 component. The precise state of tyrosinase within follicular melanocytes prior to day 5 of the hair growth cycle remains to be determined. The functional significance of the multiple forms of tyrosinase also is yet to be established.
Postural control of shell position by the abdomen of the hermit crab, Pagurus pollicarus. II. Reflex control of the ventral superficial muscles
Authors: Chapple William D. 
Published: June 2005

AbstractThe five excitors and one inhibitor which innervate each side of the ventral superficial muscles of the hermit crab are described. The longitudinal layer receives three excitors, one of which phasically activates a lateral strip of muscle, the second tonically drives a ventromedial strip and the third innervates a strip between the other two. The inhibitor innervates the last two regions of longitudinal muscle as well as the circular muscle. Two excitors, a phasic and a tonic fiber innervates adjacent longitudinal regions of the circular muscles, but less is known of their reflex behavior. In all cases, the tonic frequency of units on the right was less than their homologues on the left, but this asymmetry was reversed during a reflex discharge. Isolation of the ganglion increased the asymmetry of spontaneous activity. It is suggested that this asymmetry may not have any functional importance but instead may be related to the different sizes of motoneurons on the two sides.
Postural control of shell position by the abdomen of the hermit crab, Pagurus pollicarus. III. Analysis of movements and calculations of forces exerted by the muscles
Authors: Chapple William D. 
Published: June 2005

AbstractExperiments with a transparent plastic snail shell indicated that the hermit crab carries the columella in the crook of its bent abdomen. There are three components to the normal curvature of the abdomen in the region of the third segment, a ventroflexion of 30°, a pitch to the right of 10°, and a clockwise rotation of 20° of the whole abdomen about the thoracic‐abdominal junction. The forces and bending moments produced by the ventral superficial muscles were estimated from the sizes of the muscles, their position on the circumference of the abdomen, the amplitudes of the EJPs of the motoneurons, and their firing frequency. These calculations are in reasonable agreement with the behavioral measurements.
Development of transferred ferret eggs in relation to the age of corpora lutea
Authors: Chang M. C. 
Published: June 2005

AbstractFerret eggs recovered from oviducts and uteri at various times after insemination were transferred to the uteri of recipient animals on various days of pseudopregnancy. Fifteen per cent of newly fertilized two day eggs recovered from oviducts were implanted when transferred to uteri of two‐day pseudopregnant ferrets but only 5% developed to fetuses. Synchronous transfer of four‐, six‐, seven‐ and eight‐day eggs to uteri of four‐, six‐, seven‐ and eight‐day pseudopregnant ferrets resulted in 44‐62% of implantations, but only 21–41% of eggs developed to fetuses. Twenty‐one‐fifty‐seven percent of eggs were implanted, and 8–29% of eggs developed to fetuses when eggs were transferred to uteri of ferrets that had ovulated two days later. When transferred to uteri of ferrets that had ovulated two days earlier none developed to fetuses although 33–50% of transferred eggs implanted. No fetal development was observed when six‐day eggs were transferred to estrous ferrets treated with various progestins, but a few implantations (3–17%) occurred.
Lactate dehydrogenase lsozymes of the penguin Pygoscelis adeliae
Authors: Markert Clement L. , Mausi Yoshio 
Published: June 2005

AbstractThe complex isozyme patterns of lactate dehydrogenase (LDH) in penguin (Pygoscelis adeliae) tissues were examined at several successive stages in embryonic development by starch‐gel electrophoresis. The relative quantities of the isozymes were measured by densitometry, and the subunit composition of each isozyme was analyzed by molecular hybridization. The complexity of the isozyme pattern varied greatly with the conditions of electrophoresis but maximum resolution was obtained with a neutral Tris‐citric acid buffer of low ionic strength. When electrophoresis was carried out with this buffer at 4°C, as many as fifteen isozymes were resolved. Only five isozymes can be distinguished at high ionic strength. The fifteen isozymes can be classified into five groups, each group corresponding to one of the five major LDH isozymes found in mammals and birds. The validity of this classification was tested by molecular hybridization with beef and horse LDH, the subunit composition of which is known. The pattern of hybrid molecules produced suggests that penguin LDH contains three different subunits that may generate fifteen isozymes by random association as tetramers. To test the binomial proportions among the isozymes a quantitative photometric assay was developed for measuring enzyme activity in terms of formazan deposited on a starch gel during the staining reaction for LDH. Only at low enzyme concentrations is the deposited dye linearly proportional to the amount of enzyme. The relative abundance of the isozymes in most tissues approximated a binomial distribution. Tissue spcific patterns revealed that anodal isozymes predominate in heart, ovary and liver and cathodal isozymes in lung and muscle. However, in contrast to mammalian tissues, the penguin patterns are not sharply skewed. All isozymes are reasonably abundant in all adult tissues. In early embryonic stages of development all tissues contained greater proportions of LDH‐1, but a shift in isozyme distribution gradually took place during the course of development to enrich enzyme activity at the LDH‐5 end of the spectrum in late embryonic and adult tissues.
Reversible effects of antimitotic agents on cortical morphogenesis in the marine ciliate Condylostoma magnum
Authors: Tartar Vance , Pitelka Dorothy R. 
Published: June 2005

AbstractEffects of antimitotic agents on morphogenesis in the marine ciliate Condylostoma were tested. Surgically transected cells or early predividers were placed in solutions of Colcemid, colchicine, vinblastine, griseofulvin, or chloral hydrate in varying concentrations and for varying periods of time. Although early dividers proceeded to complete cytokinesis and, in at least some instances, macronuclear fission while in the drug solutions, development of normal form and oral organelles in daughter cells and regeneration and remodeling in operated fragments were completely blocked by appropriate drug concentrations. Inhibition was in almost all cases reversible: blocked cells, when washed and returned to sea water, underwent normal morphogenesis.Like other ciliates, Condylostoma has in its ectoplasm highly organized systems of microtubules associated with kinetosomes of the body ciliature and the oral apparatus. Electron micrographs of Colcemid‐treated cells show that preexisting cortical microtubules are not destroyed by treatments that prevent morphogenesis. They thus resemble ciliary and kinetosomal microtubules of other cells in being resistant to agents that cause the disappearance of most cytoplasmic and spindle microtubules.Most of the recognizable events of morphogenesis involve the growth and migration of microtubular organelles, and these events did not occur in the presence of the inhibiting agents. It is concluded that microtubule growth is necessary for the development of structure and pattern in Condylostoma.
Effects of bilateral limb‐bud extirpation on motility and prehatching behavior in chicks
Authors: Helfenstein Myrna , Narayanan C. H. 
Published: June 2005

AbstractThe role of sensory input in the performance of overt motility by the chick embryo has been a matter of controversy. Although it has been proven that embryonic motility is generated in the motor system of the spinal cord and does not require sensory input up to 15 days, it has been suggested that self‐stimulation and related “experiences” during embryonic development are instrumental in the structuration or facilitation of normal embryonic and post‐hatching motor patterns. Using microsurgical techniques, hind‐limb buds were extirpated bilaterally in chick embryos at three days of incubation in order to eliminate a major source of self‐stimulation to the head by the legs. The total motility of legless chicks in not significantly different from that of the control embryos between 11 and 17 days. Part of the pre‐hatching and hatching behavior repertory is also performed normally by the legless embryos. However, they do not hatch, probably because the bracing of the tarsal joints against the shell is necessary for the rotatory movements during hatching. Feeding, drinking and righting after hatching are normal.
Modification of regeneration in Dugesia tigrina by actinomycin D
Authors: Ansevin Krystyna D. , Wimberly Marilyn A. 
Published: June 2005

AbstractDifferences in regeneration of isolated postpharyngeal body sections were observed in two laboratory groups of Dugesia tigrina. One group regenerated 14.8% of bipharyngeal specimens, which in some cases, also showed abnormal polarity. The other group regenerated only 1.19% of bipharyngeal forms under similar conditions, with no indications of seriously deviant polarity.In the first strain, the application of actinomycin D at early stages of regeneration of the body sections increased greatly the incidence of multipharyngeal regenerates (with 2–5 pharynges); it also slightly enhanced the occurrence of abnormal polarity in the reconstituted worms. In the second strain, the increase in percentage of bipharyngeal forms regenerated from similar body fragments was insignificant (up to 5%). It was without effect on either strain if introduced to the regenerating sections at later stages of regeneraton. A test for incorporation of 32P into RNA showed that actinomycin, as used in the present study, suppressed over 90% of synthesis of total RNA in the regenerating body fragments.From these findings a hypothetical model is developed to explain reorganization in the isolated postpharyngeal section as a sequence of certain local inductions and inhibitions of differentiation. The significance of synthesis of RNA in relation to these developmental events is discussed.