bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro release of lectins from Phallusia mamillata hemocytes after their fractionation on a density gradient
Authors: Cammarata Matteo , Parrinello Nicolo , Arizza Vincenzo 
Published: June 2005

AbstractHemocytes were fractionated by centrifugation on a discontinuous Percoll density gradient from the hemolymph of Phallusia mamillata. Results obtained from microcultures of the fractionated hemocytes, sugar‐inhibition experiments, SDS‐PAGE, and immunoblotting indicate that “compartment cells” release cellular‐type (CL) lectins that are specific for α‐lactose and lactulose. The released lectins have the same properties as the CL lectins that were previously isolated from sonicated unfractionated hemocytes, but they differ in terms of some molecular and immunological properties from the lectins (SL) purified from the serum. SLs were never found in the supernatants from microcultures of the fractionated hemocytes. © 1993 Wiley‐Liss, Inc.
Immunological detection of an oviductal glycoprotein in the rat
Authors: Abe Hiroyuki , Abe Miki 
Published: June 2005

AbstractIn the golden hamster, high‐molecular‐weight glycoproteins are secreted by the epithelial cells of the oviduct. The present study was designed to investigate the possibility that the rat oviduct produces specific glycoproteins similar to the oviductal glycoproteins (GHOGPs) of the golden hamster. Oviductal extracts and oviductal fluids obtained from ovulatory rats were analysed by immunoblotting for the presence of glycoproteins that cross‐react with a monoclonal antibody (MAb) against GHOGPs. The MAb immunoreacted with a broad band of proteins with a range of molecular weights (MWs) of above 330 kD in oviductal extracts or oviductal fluid after fractionation by electrophoresis under reducing conditions, but these proteins were not present in serum and uterine flushings. An immunohistochemical study demonstrated that the MAb bound strongly to the epithelial cells of the oviduct and, to a lesser extent, to those of the large intestine. Weak reactions were also observed with some other tissues. However, similar material of high MW was not detected in extracts of tissues from the other organs, suggesting that the glycoprotein of high MW that reacted with the MAb is specific for the oviduct. Ultrastructural immunocytochemistry revealed that the MAb reacted specifically with putative secretory granules of nonciliated cells in the oviductal epithelium. These results indicate that the oviductal epithelial cells of the rat produce a specific glycoprotein that is immunologically similar to GHOGPs. © 1993 Wiley‐Liss, Inc.
Endocrine regulation of the elasmobranch reproductive tract
Authors: Callard Ian P. , Koob Thomas J. 
Published: June 2005

AbstractAlthough the rich variety of reproductive tract adaptations in elasmobranchs has been well documented and involves many variants associated with oviparity and extensive evolution of viviparity in the group, little is known of the hormone dependence of reproductive tract development, differentiation, and function in the adult. In this paper, we present a brief review of some of our observations on the subject made over the past 15 years in the context of earlier observations. In total, despite the paucity of information, the observations suggest that hormonal mechanisms of reproductive tract regulation, considered until recently to be the priority of mammals, have been in place since the era of very early vertebrate evolution, 400 million years before present. These reinforce the view that the endocrine regulatory mechanisms of reproduction in elasmobranchs may serve as models for more highly evolved mammalian species including the human. Indeed, the enormous variety of reproductive tract adaptations in elasmobranchs foreshadows those subsequently evolved in mammals, and because of transitional stages provide needed insight into process which is not possible in the study of mammals alone. © 1993 Wiley‐Liss, Inc.
Pregnancy in chiroptera
Authors: Rasweiler John J. 
Published: June 2005

AbstractAs with other aspects of their biology, bats exhibit considerable diversity in their reproductive characteristics. While early embryonic development in many species generally adheres to the pattern shown by more commonly studied eutherian mammals, others demonstrate advanced development in the oviduct (to the zona‐free blastocyst stage) and a prolonged tubal journey of the embryo in a temporal sense. In some bats, the process for transporting ova through the oviducts can distinguish between living embryos and the remnants of dead ova. Implantation in bats is unusually diverse with respect to localization of the nidation sites (which in most species seem to be predetermined), orientation of the inner cell mass during implantation, depth of implantation, and trophoblastic invasiveness. Some species which can be bred in captivity would appear to be promising experimental models for studies of implantation because both this process and their endometrial biology in general exhibit many similarities to those of humans. Depending upon the species, bats develop either endotheliochorial or hemochorial placentas. Studies on black mastiff bats (Molossus ater) indicate that maternal endometrial endothelial cells probably play a very important morpho‐genetic role during placental development in this species. Similarities in placental structure suggest that this may also be the case in a number of other eutherian mammals. © 1993 Wiley‐Liss, Inc.
Implantation: A cell biological paradox
Authors: Denker H.‐W. 
Published: June 2005

AbstractImplantation initiation in eutherian mammals requires, at least in invasive types of implantation, that 1) the trophoblast or subpopulations of it have reached a state of “invasiveness” and, synchronously, 2) the endometrium has reached a state of “receptivity” (“implantation window”). The cell biological basis of “receptivity” as well as of “invasiveness” has long remained unknown, but recently it appears that the application of modern concepts of cell and developmental biology is opening new views of it, concentrating on cell adhesion and cell polarity phenomena.Implantation initiation requires that the trophoblast attaches via its apical plasma membrane to the apical plasma membrane of the uterine epithelium. Since apical plasma membranes of epithelia are normally non‐adhesive, this represents a cell biological paradox. In development, cells can express two major phenotypes and switch between these: 1) the mesenchymal/fibroblastoid phenotype that is compatible with cells moving individually; 2) the epithelioid phenotype which is characterized by cells expressing apico‐basal polarity and a strong association with neighbouring cells via various junctions, so that they can migrate as sheets but not as individual cells. Application of this concept to embryo implantation would seem to lead to the hypothesis that the trophoblast of blastocysts has to give up part of its typical epithelial organization when becoming invasive; it must express cell‐cell adhesion molecules or matrix receptors non‐typically at its apical plasma membrane, change the spectrum of expressed adhesion molecules, and alter its motility apparatus. This applies in a somewhat similar way to the uterine epithelium at “receptivity.” Interestingly, recent data show that a substantial number of differentiation parameters of these cells change in addition. It appears that part of the epithelial differentiation program is down‐regulated at this phase. This also suggests interesting new aspects of the basis of steroid hormone action at the endometrium, as well as of trophoblast invasiveness, possibly involving switches in the activity of regulatory “master” genes as are also involved in decision making during development. © 1993 Wiley‐Liss, Inc.
Ultrastructural and biochemical analysis of the sarcoplasmic reticulum from crayfish fast and slow striated muscles
Authors: Ushio Hideki , Watabe Shugo 
Published: June 2005

AbstractUltrastructural and biochemical properties were compared between two types of the sarcoplasmic reticulum (SR), one from the deep extensor abdominal muscle medialis (fast muscle) and the other from the flexor muscle of carpopodite in meropodite (slow muscle) of crayfish Procambarus clarkii. Electron microscopic observations revealed that terminal cisternae of the SR of crayfish fast muscle was well‐developed and contained feet‐like structures. In transverse sections, the SR of slow muscle was tubule‐like in shape and the terminal cisternae of the SR occupied smaller area than those of the fast muscle SR. The fragmented SR obtained from the homogenized fast muscle was poorly separated by ultracentrifugation with a sucrose gradient (25–50%): both vesicles from light and heavy fractions contained terminal cisternae and were connected to transverse tubules via the feet‐like structures. In contrast, the slow muscle fragmented SR could be separated in to the light and heavy fractions, which contained elliptical vesicles and vesicles with the feet‐like structures, respectively. Sodium dodecyl sulfate (SDS)‐polyacrylamide gel electrophoresis and subsequent 45Ca ligand overlay analyses revealed that a 105,000 ( =105 k) Da protein was the major protein in both SRs, which lacked Ca2+‐binding proteins corresponding to vertebrate calsequestrins. On the other hand, peptide‐mapping of the 105 kDa protein in SDS‐gels suggested no difference in the primary structure between fast and slow SR. Ca2+‐ATPase and Ca2+ uptake activities of the fast muscle SR at 20°C were 0.39 μmol Pi/min·mg and 0.57 μmol Ca/min·mg, respectively, which were clearly higher than those of the slow muscle SR, 0.27 μmol Pi/min·mg, and 0.37 μmol Ca/min·mg, respectively.These results suggest that the SR of crayfish fast and slow muscles were morphologically and enzymatically different, which might partly cause differences in the contractile properties of fast and slow muscles. © 1993Wiley‐Liss, Inc.
The energetics of osmotic regulation in ureotelic and hypoosmotic fishes
Authors: Kirschner Leonard B. 
Published: June 2005

AbstractThe major mechanisms of urea turnover and of active ion transport in osmoregula‐ tory organs are reviewed. Using published values for the molecular flow through these systems it is possible to estimate the energetic cost of osmotic regulation in hyporegulating marine teleosts and in ureotelic elasmobranchs. Oxygen consumption dedicated to osmotic regulation in the flounder (Platichthys flesus) is about 7 ml kg−1 hr−1 and in the rainbow trout (Salmo gairdneri) 6 ml kg−1 hr−1 For a dogfish (Scyliorhynus canicular) it was 5 ml kg−1 hr−1 and for the skate (Raja erinacea) 5 or 11 ml kg−1 hr−1 based on two values for urea loss by the fish. Both groups of fish used 10–15% of their standard metabolism for osmotic regulation. There are a number of uncertainties that may require modification of these values. It is not known whether TMAO lost by ureotelic regulators is replaced by ingestion or by synthesis. If by synthesis, the cost of regulation would be higher than calculated. Even more serious is the uncertainty regarding the use of organic osmolytes to maintain equilibrium between cells and blood. This strategy almost certainly requires some energy input, but there is insufficient information to permit its quantitative estimation, so the factor was omitted from the calculation. Among hyporegulators the sole unknown is whether the esophagus may absorb some of the ingested salt by diffusion. If so, it would decrease the energy expended in the intestinal tract and lower the total cost of regulation. The conclusion, based on known factors for the species examined, is that both modes are about equally efficient. If it becomes possible to factor in the unknowns it may be that hyporegulation is slightly more economical than ureosmotic. © 1993 Wiley‐Liss, Inc.
Egg capsule structure and permeability in the viviparous shark, Mustelus canis
Authors: Lombardi Julian , Files Tamarah 
Published: June 2005

AbstractThe structure and permeability characteristics of egg capsules of the viviparous matrotrophic elasmobranch Mustelus canis were investigated by scanning electron microscopy (SEM), X‐ray microprobe elemental analysis, and through the use of modified Ussing chambers. The egg capsule surrounds the developing embryo during gestation and consists of a four or more orthogonally arranged laminae of fibrous material. SEM and energy dispersive spectroscopy (EDS) of inner and outer capsular surfaces reveal that the capsule is 4.7 μm in thickness and possesses scattered calcium deposits along its inner and outer surfaces. Transcapsular permeability studies qualitatively demonstrate that capsules are readily permeable to fast green fcf (808 Da) and rose bengal (1,000 Da). Capsules are impermeable to insulin (5, 750 Da), lysozyme (14,300 Da) and bovine albumin (66,000Da). Glucose (P= 3.3 × 10−4 ± 1.2 × 10−4cm/sec[n = 120])and urea(P= 4.5 × 10−4 ± 2.3 × 10−4cm/sec [n = 139]) readily pass across the egg capsules. It is suggested that maternal‐embryonic nutrient transfer primarily involves the transcapsualr passage of low (<5 kDa) molecualr weight components. These data are discussed in relation to the mechanisms of placental attachment in matrotrophic sharks. © 1993 Wiley‐Liss, Inc.
Effects of protease inhibitors on binding of sperm to the vitelline coat of ascidian eggs: Implications for participation of a proteasome (multicatalytic proteinase complex)
Authors: Takizawa Satoshi , Sawada Hitoshi , Someno Tetsuya , Saitoh Yoshiko , Yokosawa Hideyoshi , Hoshi Motonori 
Published: June 2005

AbstractAmong various protease inhibitors, chymostatin (an inhibitor of sperm chymotrypsinlike protease) strongly inhibited the binding of sperm to the vitelline coat of glycerinated eggs of the ascidian Halocynthia roretzi, whereas leupeptin (an inhibitor for sperm acrosin), antipain, and soybean trypsin inhibitor had no significant inhibitory effects. Dansyl‐Val‐Pro‐argininal (an inhibitor of the sperm trypsin‐like protease, spermosin) had an inhibitory effect on the binding of sperm that was much smaller than its effect on fertilization. Since the sperm chymotrypsin‐like protease that is involved in ascidian fertilization has been identified as a proteasome (multicatalytic, proteinase complex), we tested the effects of several peptidyl argininals, inhibitors of the activities of proteasomes, on this binding process. The ranking of the inhibitory effects of these compounds on the binding of sperm was the same as that of their effects on the chymotrypsin‐like activity of the proteasome, reported previously. The potent inhibitors of binding used in these studies had no or minimal effects on sperm motility. These results suggest that a sperm chymotrypsin‐like protease (most probably the chymotrypsin‐like protease in the proteasome) plays a key role in binding of sperm to the vitelline coat of the ascidian egg. © 1993 Wiley‐Liss, Inc.
Significance of circulating catecholamines in regulation of trout splanchnic vascular resistance
Authors: Xu Hao Y. , Olson Kenneth R. 
Published: June 2005

AbstractIt has been generally presumed that circulating catecholamines have little if any effect on systemic vascular resistance in resting trout; however, this question has not been directly addressed. In the present study, the response of isolated vessel rings and perfused tissues to catecholamines and the importance of circulating epinephrine in the vasoconstrictor response of the splanchnic circulation to splanchnic nerve stimulation were examined. Epinephrine (EPI) and norepinephirine (NEPI) produced dose‐dependent contractions of celiacomesenteric (CM) and epibranchial (EB) arteries, anterior cardinal (AC) veins, and increased vascular resistance in the perfused dorsal aorta (PDA; skeletal muscle‐kidney‐distal intestine) and perfused celiacomesenteric (PCM; splanchnic) vascular beds. In all instances the threshold catecholamine concentration for in vitro vasocnstriction was greater than plasma atecholamine concentrations in vivo. Neither EPI nor NEPI contracted ventral aorta rings. Addition of non‐constrictor, but physiological, concentrations of EPI to the perfusate (10‐9M) tripled the increase in PCM resistance produced by splanchnic nerve stimulation. Perfusate EPI also prevented or reversed splanchnic nerve fatigue and restored PCM resistance in fatigued preparations. These results indicate that a direct effect of circulating EPI may be an important source of neuronal catecholamine uptake and may be required to sustain neuronal sympathetic tone. © 1993 Wiley‐Liss, Inc.
Periventricular nucleus lesioning modulates specific somatostatin binding in various brain regions and anterior pituitary
Authors: Sabry Ismail , Suzuki Mitsuo , Shigematsu Kazuto , Kakegawa Tadao 
Published: June 2005

AbstractThe effects of periventricular nucleus (Pe) lesioning on the plasma growth hormone (GH) levels and the anterior pituitary (A.P.) and brain somatostatin (SRIF) receptors were studied. A transient significant increase in plasma GH level in lesioned rats was detected 1 day after the were paralleled by an increase in binding of 125I‐Tyr11‐SRIF‐14 to the A.P. 1 day after lesioning. This result could further confirm that the SRIF inhibitory action on GH release takes place at the A.P. level. Also, a transient increase in binding of the radioligand was detected in some brain areas 1 and 4 days after the lesion. However, the mechanism by which this increase takes place remains to be elucidated. © 1993 Wiley‐Liss, Inc.
Inter‐ and intraspecific distribution of an antigenic epitope found in an inbred strain of the Medaka, Oryzias latipes
Authors: Matsuzaki Takashi , Sakaizumi Mitsuru , Shima Akihiro 
Published: June 2005

AbstractWe attempted to produce monoclonal antibodies against strain‐specific antigens of the Medaka, Oryzias latipes, using eight inbred strains and several wild populations. One monoclonal antibody, named m11C1, showed reactivity to the cells of one inbred strain HB11C but not to the cells of the other inbred strain HNI. The reactivity was also found for the cells of four other inbred strains but not to that for two inbred strains. To understand the character of the antigen recognized by the m11C1, wer examined wild populations of the Medaka in regard to reactivity for the m11C1. Among fish collected from 122 localities, the m11C1 exclusively recognized the cells of the fish which were classified as the Southern Population. None of the fish from the Northern, the East Korean, and the China‐West Korean Populations reacted with the m11C1 antibody. Thus, the antigen recognized by the m11C1 was named SA1 (Southern Population‐specific Antigen 1). The SA1 antigen from liver cells appeared as a single band on Western blot with a molecular mass of 31 kDa. This antigen mainly localized in epithelia of intestinal vili and in melano‐macrophages which were frequently observed in spleen and anterior kidney. Genetic corsses suggested that SA1‐positive phenotype was dominant. Moreover, SA1 was also detected in two closely related species, O. luzonensis and O. curvinotus, but not in less‐ related five species of the genus Oryzias. Origin and propagation of the SA1 antigen were discussed based on geographic and phylogenic distribution pattern of SA1. © 1993 Wiley‐Liss, Inc.
Isosmotic modulation of cell volume and intracellular ion activities during stimulation of single exocrine cells
Authors: Foskett J. Kevin , Wong Monica M. M. , Sue‐A‐Quan Greg , Robertson Marli A. 
Published: June 2005

AbstractStimulation of salivary secretion is associated with a rise of [Ca2+]i in acinar cells. We examined the osmotic and ionic consequences of activation of Ca2+‐dependent K+ and Cl− channels, by simultaneous optical determinations of cell volume and [Ca2+]i, [Cl−]i or [Na+]i during muscarinic stimulation of single salivary acinar cells, using a differential interference contrast (DIC)‐fluorescence microscope. Carbachol caused a rapid rise of [Ca2+]i, as well as a substantial cell shrinkage. Despite variability in the level and kinetics of the subsequent sustained phase of the [Ca2+]i response, cell volume was correlated with [Ca2+]i in all cases. Elevated [Ca2+]i was both necessary and sufficient to cause these changes in cell volume. The proposition that changes in cell volume reflected changes in cell solute content was confirmed by simultaneously measuring [Cl−]i and cell volume. Simultaneous determinations of cell volume and [Na+]i indicated that the initial cell shrinkage was due entirely to K+ and Cl− efflux. Subsequent to the initial shrinkage, [Na+]i rose to high levels, primarily due to activation of Na+/H+ exchange. Thus, modulation of ion transport activities under isosmotic conditions results in substantial changes in cell solute content and cell volume. Subsequent to the early Ca2+‐induced changes in these parameters, other transporters become active, but it is unclear what signals their activation. Cell swelling by osmotic dilution of the bath resulted in compensatory cell shrinkage (RVD) which was sensitive to K+ and Cl− gradients. Nevertheless, a rise of [Ca2+]i was not necessary for RVD. Osmotic shrinkage and/or cell acidification were insufficient to activate Na+ influx. Our data suggest that the intracellular signalling pathways used by cells to activate ion transport under anisosmotic conditions may not be the same as those employed under isosmotic conditions. © 1994 Wiley‐Liss, Inc.
Osmolyte permeability in molluscan red cells is regulated by Ca2+ and membrane protein phosphorylation: The present perspective
Authors: Pierce Sidney K. 
Published: June 2005

AbstractDuring the past several years, a number of studies on a variety of cell types have demonstrated the importance of Ca2+ in the control of the mechanism that produces cell volume recovery following a hypoosmotic stress. We have been studying the details of this control using the red blood cell from the bivalve mollusc, Noetia ponderosa, as a model. Volume recovery by these molluscan cells is a Ca2+‐sensitive process that involves initial Ca2+ entry, followed by phosphorylation of certain membrane‐associated proteins and taurine efflux. This paper reviews the present state of those studies and presents a working hypothesis of the nature of the mechanism. © 1994 Wiley‐Liss, Inc.
Quantitative immunoblot detection of rare proteins in whole cell extracts using biotin‐strepavidin reagents
Authors: Stevenson Bruce R. , Richards Cheryl L. , Howarth Andrew G. , Maraj Vikram A. , Hibbard Jennifer G. 
Published: June 2005

AbstractA novel immunoblotting method designed for quantitative detection of low copy‐number proteins in crude cell extracts is presented. This technique can be used with either mono‐ or poly‐clonal antibodies and utilizes the sensitivity and amplification of the high affinity interaction between biotin and strepavidin. Radioactive iodination of the strepavidin moiety allows for rapid and accurate quantification of proteins bound to nitrocellulose. This biotin/125I‐strepavidin technique is highly reproducible and can detect as little as 1 ng of protein. In addition, use of biotinylated secondary antibodies directed against a specific type of primary antibody avoids the problem of low affinity recognition of immunoglobulins from certain species by protein A. Finally, the methodology is simple and convenient, and secondary and tertiary reagents are commercially available. The application of this technique is illustrated in the determination of relative quantities of the tight junction‐associated protein ZO‐1, present in very small amounts in epithelial cells. This same technique can also be used for the quantitative analysis of relatively more abundant cellular constituents or purified protein. © 1994 Wiley‐Liss, Inc.