bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of embryo‐toxic ammonium from the culture medium by in situ enzymatic conversion to glutamate
Authors: Lane Michelle , Gardner David K. 
Published: June 2005

AbstractAn enzymatic method for removing embryo‐toxic ammonium from culture medium has been developed. Ammonium, produced by both embryo metabolism and spontaneous breakdown of amino acids at 37°C, is transaminated by glutamate dehydrogenase to nontoxic glutamate. Initially, the individual components of the transamination reaction were titrated against mouse embryo development in vitro to determine embryo‐safe levels. ADP, an allosteric activator of glutamate dehydrogenase, was found to inhibit embryo development and was therefore omitted from the final formulation (α‐ketoglutarate, 0.44 mM; glutamate dehydrogenase, 0.375 U; NADH, 0.12 mM). It was found that 0.30 mM ammonium could be removed from the culture medium in situ in 3 h. In situ removal of ammonium significantly increases both blastocyst cell number, implantation, fetal development, and fetal weight after transfer. Removal of ammonium by the conventional method of renewing the culture medium also increased blastocyst cell number but did not affect postimplantation development. In conclusion, it is possible to alleviate the toxic effects of ammonium in vitro on pre‐ and postimplantation mouse embryo development by its transamination in situ. Thereby facilitating the continual exposure to embryo‐derived factor(s) which stimulates both pre‐ and postimplantation development. © 1995 Wiley‐Liss, Inc.
Embryonic growth and maternal nutrient sources in goodeid fishes (Teleostei: Cyprinodontiformes)
Authors: Hollenberg Frank , Wourms J. P. 
Published: June 2005

AbstractMost species of the viviparous teleost family Goodeidae exhibit an unusual placental relationship. Embryos lay free within the single, hollow ovary where they are bathed by the ovarian fluid. Nutrients are absorbed from the fluid through distinctive perianal processes called trophotaeniae. Trophotaeniae represent the embryonic component of the placenta and may be functionally divided into protein endocytosing and nonendocytosing types. The maternal component of the placenta is the internal ovarian epithelium (IOE). Since embryos undergo dry weight increases ranging from 68‐ to 387‐fold compared to the dry weight of mature ova, there must be substantial nutrient transfer from the maternal organism during gestation. Transmission electron microscopy of the IOE of gravid females of three goodeid species fails to reveal evidence of significant synthetic activity by the IOE, although occasional budding of parts of IOE cells occur, and the IOE of one species, G. atripinnis, contains substantial amounts of lipid. Electrophoretic comparison of nongravid females of two species establishes that the protein pattern of the ovarian fluid is similar to that of the female blood serum. In gravid females whose embryos bear protein‐endocytosing trophotaeniae, protein is undetectable in the ovarian fluid during mid‐ and late gestation, suggesting efficient protein absorption by the trophotaeniae. In gravid females whose embryos bear nonendocytosing trophotaeniae, serum proteins are present in the ovarian fluid at midgestation, but are reduced to only a trace at late gestation suggesting possible imbibition by the embryos. © 1995 Wiley‐Liss, Inc.
Lipovitellin and lipid droplet accumulation in oocytes during ovarian maturation in the blue crab, Callinectes sapidus
Authors: Lee Richard F. , Walker Anna 
Published: June 2005

AbstractBlue crab ovaries rapidly increased in weight during the 30 days after the terminal molt into adulthood. Oocytes isolated from ovaries during this period increased in diameter from 40 to 201 μm. The concentrations of lipovitellin, a high density lipoprotein found in oocytes, were determined by a competitive ELISA procedure using a monoclonal antibody against one of the lipovitellin peptides. Lipovitellin and lipid droplets were minor components in the immature ovaries and oocytes but increased in concentration to become the major components of the mature ovaries and oocytes. In mature oocytes (201 μm diameter) lipovitellin concentrations accounted for 35 and 95% of the total oocyte protein and soluble oocyte protein, respectively. In mature oocytes the total lipid, lipovitellin lipid, and lipid droplet concentrations were 510, 240, and 140 ng/oocyte, respectively. Sections of ovaries and hepatopancreas at different stages of maturation were probed with the anti‐lipovitellin antibody. In small immature oocytes, where no yolk was present, the immunoreactivity was confined to perinuclear yolk complexes. The immunoreactivity of more mature oocytes was associated with globular structures in the cytoplasm. Neither ovarian follicle cells nor hepatopancreas cells showed immunoreactivity. Our results suggest that in blue crabs the lipovitellin components are primarily synthesized in the developing oocytes with perinuclear yolk complexes playing an important role in the formation of lipovitellin‐rich yolk granules. Scattered collections of presumed phagocytic hemocytes contained immunoreactive granular material in their cytoplasm. We suggest that these hemocytes remove debris from oocytes which fail to reach maturation and carry this debris to the hepatopancreas. © 1995 Wiley‐Liss, Inc.
In vitro hepatocyte metabolism of alanine and glucose and the response to insulin in fed and fasted rainbow trout
Authors: Pereira C. , Vijayan M. M. , Moon T. W. 
Published: June 2005

AbstractRainbow trout (Oncorhynchus mykiss) fasted for 4 months had lower plasma glucose concentration and hepatocyte glycogen content than the fed fish. Gluconeogenesis from alanine in the fasted fish was not significantly different from that of the fed fish, Whereas both alanine glyconeogenesis and oxidation increased with fasting by 400% and 300%, respectively. Glyconeogenesis from glucose was not significantly different with fasting, whereas glucose oxidation decreased significantly with fasting. The presence of glucose (10 mM) in the medium did not modify alanine glyconeogenesis or gluconeogenesis in either the fed or the fasted groups. However, glucose did increase alanine oxidation in the fed group but not in the fasted group, this response being further stimulated in the presence of insulin. Alanine (2 mM) in the medium had no effect on glyconeogenesis from glucose in either fed or fasted trout hepatocytes. Insulin significantly decreased glucose oxidation in the fed fish, whereas the insulin effect on glucose oxidation in the fasted fish occurred only in the presence of alanine. The results indicate that nutritional state affects hepatocyte responsiveness to substrate utilization and insulin stimulation in trout. Specifically, the hepatocyte potential for glyconeogenesis is enhanced in the fasted fish, although this increased glycogen production is not due to an increased glucose utilization. © 1995 Wiley‐Liss, Inc.
Bh(black at hatch) gene appears to cause whole‐body hemorrhage in homozygous embryos of Japanese quail (Coturnix coturnix japonica)
Authors: Kubota Yukihiko , Nakamura Akira , Ito Michio , Shiojiri Nobuyoshi 
Published: June 2005

AbstractGenotypes of early embryos obtained from mating Bh/+ quail were determined by chorio‐allantoic membrane grafting of their thigh skin, and the development of The Bh homozygous embryos was examined histologically. The Bh homozygous embryos died at an early stage of development (after 7 to 10 days of incubation) with a very high incidence of whole‐body hemorrhage (approximately 100%), but malformation of neural tubes was not always accompanied by Bh homozygosity. Degeneration of the liver was more frequently observed in homozygous embryos than in wild‐type and heterozygous embryos. The results suggest that the Bh gene causes whole‐body hemorrhage and subsequent death of homozygous embryos. In addition, our data indicate that Bh homozygote would develop brown feathers on theirskin if they were able to survive. © 1995 Wiley‐Liss, Inc.
17α, 20α‐dihydroxy‐4‐pregnen‐3‐one, not its 20β isomer, is produced from 17α‐hydroxyprogesterone by spermatozoa of secondary male groupers (Epinephelus tauvina) derived from females implanted with 17α‐methyltestosterone
Authors: Tan A. M. C. , Lee S. T. L. , Kime D. E. , Chao T. M. , Lim H. S. , Chou R. , Lam T. J. , Tan C. H. 
Published: June 2005

AbstractSperm of secondary male groupers(Epinephelus tauvina), derived from females implanted with 17α‐methyltestosterone (MT), were incubated with [3H]17‐hydroxyprogesterone for 2 hr. The medium was extracted and analyzed by high performance liquid chromatography (HPLC). A single major metabolite with relative retention time corresponding to 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (17,20α‐P) was produced by the sperm. The metabolite was isopolar with 17, 20α‐P on thin layer chromatography (TLC). The presumptive identify of the metabolite was confirmed to be 17, 20 α‐P when the metabolite was oxidised by periodic acid and the derivative recrystallized with authentic androstenedione to specific constant activity. This experiment indicates that grouper sperm possess the enzyme, 20α‐hydroxysteroid dehydrogenase (20 α‐HSD), and suggests that 17, 20 α‐P may play a role in grouper reproduction. © 1995 Wiley‐Liss, Inc.
Lobster swimmerets: Muscle fiber composition and membrane definition of excitatory synapses in a predominantly fast system
Authors: Govind C. K. , Bevengut Michelle , Pearce Joanne 
Published: June 2005

AbstractThe abdomen of the lobster Homarus americanus has four pairs of segmental appendages, the swimmerets, whose rhythmic beating functions in swimming, righting responses, creating water currents, and aerating eggs. There are 24 separate muscles in each swimmeret and 21 of these are fast, based on their relatively short (4 μm) sarcomeres and six thin filaments orbiting a single thick filament. Three of the 24 muscles are slow with relatively long (7–12 μm) sarcomeres and 8–11 thin filaments surrounding a thick filament. Of the eight functional groups amongst which the 24 muscles are distributed, six groups have only fast muscles, one group has a mixture of fast and slow muscles, and one group only slow muscles. Thus the number and distribution of fast muscles in the swimmeret makes it a predominantly fast system. Motor innervation of two fast muscles in the power‐stroke group reveals numerous excitatory nerve terminals (recognized by circular synaptic vesicles) with well‐defined synaptic contacts and presynaptic dense bars or active zones. Synaptic contacts appear in the P‐face of the fractured nerve membrane as circular plateaus with sparsely distributed particles and one or two small aggregations of large intramembranous particles (putative calcium channels) representing active zones. In the complementary E‐face, synapses assume spherical outlines and active zones appear as shallow depressions. Attachment sites of synaptic vesicles appear as large pits in P‐face or protuberances in E‐face leaflets along the edge of the active zones. The surface features of excitatory synapses of fast swimmeret muscles are similar to those on other crustacean fast and slow muscles. The packing density of large intramembranous particles in the active zones also resembles that in other crustacean muscles thereby suggesting an optimal packing density for these ion channels. © 1995 Wiley‐Liss, Inc.
Time‐dependent effects of daily thermoperiods, feeding, and disturbances on scale allograft survival in the gulf killifish, Fundulus grandis
Authors: Nevid Nicholas J. , Meier Albert H. 
Published: June 2005

AbstractThe length of time required to reject scale allografts was examined in groups of male gulf killifish (Fundulus grandis) treated daily with either 4‐h thermoperiods (daily intervals of 30°C during a 20°C continuum), single meal feedings, or net‐chasing disturbances at one of six different times after the onset of daily photoperiods (LD 12:12 or LD 14:10). Scale allograft survival varied by 30–60% in each timed stimulus experiment as a function of the time of day when the stimulus was provided. The phase relationship between two circadian neuroendocrine oscillations, previously proposed to regulate physiologic and behavioral conditions in gulf killifish, may have important influences on the immune system as well. The phase of one oscillation is thought to be set by the daily photoperiod, and the other is preferentially set by the nonphotic daily stimulus. © 1995 Wiley‐Liss, Inc.
Secretory products of bovine oviductal epithelial cells support the viability and motility of bovine spermatozoa in culture in vitro
Authors: Abe Hiroyuki , Sendai Yutaka , Satoh Takeshi , Hoshi Hiroyoshi 
Published: June 2005

AbstractThe ability of secretions from the bovine oviduct to maintain the viability and motility of bovine spermatozoa was investigated by incubating frozen‐thawed spermatozoa with oviductal flushings, uterine flushings, or the medium from cultures of oviductal epithelial cells and endothelial cells. The flushings obtained from both oviducts and uteri were effective for the maintenance of the viability and motility of spermatozoa, irrespective of the stage of the estrous cycle at which they had been collected. The flushings obtained from the ampullar region of oviducts at the follicular phase of the estrous cycle were most effective for the maintenance of viability and motile activity, for example, the forward motion of spermatozoa. Sperm viability and motility were also maintained by the medium from 6‐hour culture of epithelial cells obtained from oviducts at the follicular phase of the estrous cycle. In contrast, the medium derived from bovine fetal artery endothelial cells had no significant effect on sperm viability and motility. These results suggest that the fluids of the female reproductive tract, in particular, the oviductal fluids at the follicular stage, provide a suitable environment for the maintenance of the viability and motility of bovine spermatozoa. It is also suggested that secretory product(s) of oviductal epithelial cells may play an important role in sustaining both the viability and motility of spermatozoa. © 1995 Wiley‐Liss, Inc.
Immunohistochemical detection of P‐glycoprotein in teleost tissues using mammalian polyclonal and monoclonal antibodies
Authors: Hemmer Michael J. , Courtney Lee A. , Ortego Lisa S. 
Published: June 2005

AbstractMammalian P‐glycoprotein is a highly conserved 170‐kD integral plasma membrane protein functioning as an energy‐dependent efflux pump of exogenous and endogenous lipophilic aromatic compounds entering the cell by diffusion. In this study, the tissue specificities of one polyclonal (pAb) and three monoclonal (mAbs) antibodies to mammalian P‐glycoprotein were identified in paraffin‐embedded, parasagittal whole‐body sections of the guppy Poecilia reticulata. Polyclonal antibody mdr(Ab‐1) and mAbs C219, C494, and JSB‐1 demonstrated differential staining patterns in the following tissues: bile canaliculi in the liver, exocrine pancreas, lumenal surface of the intestinal epithelium, renal tubules, interrenal tissue, branchial blood vessels, gas gland, pseudobranch, and the gill transverse septa. Positive P‐glycoprotein expression in P. reticulata correlates well with published results for homologous mammalian tissues of secretory and excretory function. These data indicate that one or more highly conserved members of the P‐glycoprotein transporter family exist in a teleost species and can be detected using commercially available mammalian antibodies. © 1995 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
Stimulation of human sperm capacitation by purified lipid transfer protein
Authors: Ravnik Stuart E. , Albers John J. , Muller Charles H. 
Published: June 2005

AbstractLipid Transfer Protein I is recognized as a key component involved in high density lipoprotein metabolism. We have been studying lipid transfer in relation to sperm capacitation, a complex series of cell surface events required for the acrosome reaction and fertilization. We have previously shown that Lipid Transfer Protein I is present and active in the female reproductive tract. In the present study, we show that purified Lipid Transfer Protein I directly stimulates human sperm capacitation, but not the acrosome reaction, in the absence of other biological effectors. These results provide strong evidence for a novel role for Lipid Transfer Protein I and reveal, for the first time, a potent activator of capacitation, prior to the acrosome reaction. © 1995 Wiley‐Liss, Inc.
CO2 transport in catheterized hydrothermal vent tubeworms, Riftia pachyptila (vestimentifera)
Authors: Felbeck Horst , Turner Patricia J. 
Published: June 2005

AbstractIsolated plumes and vestimenta of the tubeworm Riftia pachyptila were perfused to determine the form in which carbon is transported to the animal's symbionts via the circulatory system. Catheters supplying colored saline were inserted into an afferent blood vessel while samples were collected from the efferent vessel. During perfusion, the plumes were immersed in sea water containing radiolabeled CO2. The effluent showed radioactivity in inorganic carbonate (∑ CO2, sum of all forms), malate, and succinate. When isolated vestimenta were perfused with saline containing labeled CO2, labeled malate and succinate could be detected in the effluent. Carbon transport in the blood as ∑ CO2 is estimated to be of similar importance to that transported after incorporation into organic carbon. The significance for the establishment of the carbon isotope ratio of tubeworms is discussed. © 1995 Wiley‐Liss, Inc.
Causes of the differences in detection of low frequencies in the auditory receptor organs of two species of bushcrickets
Authors: Kalmring Klaus , Rössler Wolfgang , Hoffmann Elke , Jatho Martin , Unrast Clemens 
Published: June 2005

AbstractThe causes of the differential sensitivity of auditory receptor cells of two tettigoniid species to low‐frequency airborne sound were investigated with neurophysiological, neuroanatomical, and bioacoustic methods. The experiments employed adult males of the Chinese species Gampsocleis gratiosa (Decticinae) and the Australian species Mygalopsis marki (Conocephalinae). G. gratiosa emits very broad‐band songs with a fundamental frequency component at 3.8 kHz, extremely low for a bushcricket; in contrast, the songs of M. marki have a narrow‐band frequency spectrum, from 9 to 25 kHz. Accordingly, the threshold of the auditory organ as a whole is low in the low‐frequency range in the case of G. gratiosa, whereas M. marki is similarly sensitive only at frequencies above 5 kHz.The experiments were designed to reveal the origin of this sensitivity difference. One possibility considered was that low‐frequency receptors of a particularly sensitive type are present in G. gratiosa and not in M. marki; alternatively, with a similar complement of receptor cells the whole‐organ threshold curve might be expanded or restricted as a result of differences in the lower cutoff frequency of the sound‐conducting system.The results confirm the latter interpretation. The proximal crista acustica and the distal intermediate organ comprise the same numbers and types of cells in the two species, and the difference in threshold of the low‐frequency receptors is produced by a shift of the frequency range in which the acoustic trachea has an amplifying effect. © 1995 Wiley‐Liss, Inc.
Female reproductive properties and prenatal development of a senescence‐accelerated mouse strain
Authors: Miyamoto Hajime , Manabe Noboru , Mitani Yukiko , Sugimoto Nami , Watanabe Takeshi , Aruga Chinami , Sato Eimei 
Published: June 2005

AbstractFemale reproductive properties, early embryonic development, and serum estradiol and progesterone levels of the senescence‐accelerated mouse (SAM)‐prone (SAM‐P) strain were compared with those of a SAM‐resistant (SAM‐R) strain. The reproductive life span of SAM‐P (from 11.4 to 25.0 weeks old) was shorter than that of SAM‐R (11.1 to 41.6 weeks old), and the total number of SAM‐P pups was 41.7% less than from SAM‐R. The reproductive senescence of SAM‐P is more accelerated than that of SAM‐R. At 15 weeks old, the maximum litter size of SAM‐P was noted and was 33.7% smaller than that of SAM‐R. Although no differences in the numbers of ovulated and fertilized ova were observed between two strains, the number of implants in SAM‐P was 21.6% less than in SAM‐R. Cell cleavage was delayed in embryos of SAM‐P (8% morula, at day 2 of pregnancy) compared to SAM‐R (48%). At day 3 of pregnancy, 9% and 33% of the embryos were blastocysts in SAM‐P and SAM‐R, respectively. At day 1 of pregnancy, serum estradiol level in SAM‐P was 18.2% higher than in SAM‐R, whereas the serum progesterone level in SAM‐P was 46.2% lower than in SAM‐R. The unbalance of estradiol and progesterone levels in SAM‐P was considered to be the cause of the delay in early embryonic development, and then the decrease of implantation and a smaller litter size. © 1995 Wiley‐Liss, Inc.
Monoclonal antibody against a 52 K sperm surface protein inhibits sperm–zona pellucida interactions in the rat
Authors: Dias Alves Marlene S. , Martins Maria Sonia , Pena Sérgio D. J. 
Published: June 2005

AbstractA major regulatory site for species specificity of fertilization in mammals lies at the level of sperm binding to the zona pellucida. This implies a high degree of complementarity between gamete and receptor molecules. These molecules support species‐specific interactions between sperm and oocyte that lead to gamete fusion (fertilization). We identified a rat sperm head surface antigen using an IgG1 monoclonal antibody (HD1) against rat sperm of epididymis cauda. By electron microscopy the antigen was shown to be present on the plasma membrane surface of the sperm dorsal head. One‐ and two‐dimensional immunoblotting analysis of sperm proteins demonstrated that HD1 reacted only with a 52 K molecule with a pI ranging from 6.6 to 7.2. The 52 K protein was first detected in situ by indirect immunofluorescence and showed to be underlining few elongated spermatids in testis. However, when the sperm reached the epididymis caput, the antigen was seen to be expressed on the dorsal surface of spermatozoa head. A similar fluorescence reaction was detected on sperms in the epididymis corpus and cauda. The specific spermato‐zoa‐zona pellucida interaction was inhibited in the presence of monoclonal antibody HD1 in a sperm binding assay of in vitro fertilization. © 1995 Wiley‐Liss, Inc.