bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitochondria in liver cells of fed and starved salamanders
Authors: McCurdy Mary Burton Derrickson 
Published: February 2005

AbstractIn the hepatic cells of well‐fed salamanders (Triturus pyrrhogaster) elongated mitochondria predominate which exhibit a diversity of shapes. Starvation tends gradually to produce a shift in predominance from the elongated to the granular forms of mitochondria; terminally looped and ring‐shaped mitochondria also characteristic of the well‐fed condition, gradually become rare to absent. Beaded elongated mitochondria increase in number after short periods of fasting, and appear to be transitional between smooth elongated mitochondria and granular mitochondria.Re‐feeding tends to bring about a recovery of the mitochondrial picture of the well‐fed animals.There are exceptions to the above general trend which show that the length of starvation and digestive activity are not the only factors that account for the changes in the mitochondrial condition. A closer relation is found between the mitochondrial condition and the relative amounts of fat and glycogen in the cell. It can be stated as a rule that the shift in predominance from elongated mitochondria to granular mitochondria parallels the decrease in amount of fat and glycogen in the cell.
Glands in the head capsule of coccinellid beetles with a discussion on some aspects of gnathal glands
Authors: Pradhan S. 
Published: February 2005

AbstractGlands are classified by structure as multicellular complex acinose, multicellular simple tubular, and unicellular; by position as general, hypodermal, ocular, anternnal, intra‐mandibular, mandibular, mandibulo‐maxillary, maxillary, intra‐cardonal and labial. Some open outside the extra‐oral cavity. They are supposed to be offensive in function. The segmental origin of the gnathial is doubtful.
Public–private partnerships in the defence industry and the extended corporate intelligence and national security model
Authors: Trim Peter 
Published: February 2005

Abstract

This article confirms that public–private partnerships in the defence industry share both economic and political dimensions.
Restructuring and consolidation will result in greater strategic integration and firmer links between defence companies and government.
Tasks currently undertaken by independent security companies can also be performed by government intelligence and security agencies.
By drawing on the knowledge of defence industry experts it is possible to provide a more comprehensive understanding of what corporate intelligence is.
Corporate intelligence is establishing itself as a separate body of knowledge.

Copyright © 2001 John Wiley & Sons, Ltd.
Immunization of female rabbits with heat‐solubilized bovine zonae: Production of anti‐zona antibody and inhibition of fertility
Authors: Gwatkin R. B. L. , Williams D. T. 
Published: February 2005

AbstractBovine zonae were solubilized by heating to 80°C in buffered saline. On injection of female rabbits with this solution, zona‐specific antisera were produced that could be assayed on bovine eggs in vitro by immunofluorescence, coating, and inhibition of sperm‐binding. When the latter was complete, the rabbits were found to be infertile. Immunofluorescence assays showed that the rabbit anti‐bovine zona serum reacted as strongly with rabbit and rhesus monkey zonae as with homologous zonae. Strong cross‐reaction was also observed with marmoset and dog zonae, but with hamster zonae the reaction was relatively weak.
Respiration rates and sugar utilization by marsupial spermatozoa
Authors: Rodger John C. , Suter D. A. I. 
Published: February 2005

AbstractThis paper reports the first metabolic study of marsupial spermatozoa. The oxidative metabolism of the spermatozoa of the Australian brush‐tailed possum (Trichosurus vulpecula) was examined using a micro Warburg system. Semen was collected by electro‐ejaculation and washed twice in Ca2+ free Krebs‐Ringer‐phosphate buffer containing antibiotics (KRPA). Washed spermatozoa suspended in fresh KRPA, were then incubated for 3 hours at 37° C in the presence and absence of added substrates (4 mM). The exogenous substrates tested were N‐acetylglucosamine, glucosamine, and glucose. Small quantities of radioactively labeled [14C] substrates were included in the incubation media to allow measurement of substrate oxidation.Although the respiratory rate varied considerably between semen pools (replicate experiments), the relationship between total oxygen consumption (measured manometrically), and oxygen consumption accounted for by exogenous substrate utilization (calcuated from radioactivity recovered in the respiratory CO2) was remarkably consistent. Oxidation of exogenous substrate accounted for 49–54% of the oxygen consumption, depending on the substrate used. There was, however, no evidence that addition of these substrates stimulated the respiratory rate over that found when no substrate was added. Lactate formation accounted for the greater part of exogenous substrate consumed.
Adenosine 3′,5′‐cyclic monophosphate‐binding protein in sea urchin eggs and embryos
Authors: Fujino Yukio , Yasumasu Ikuo 
Published: February 2005

AbstractAdenosine 3′,5′‐cyclic monophosphate (cAMP) binds to high‐molecular substances which are probably proteins, in homogenates of sea urchin eggs and embryos. The bound cAMP is exchangeable. Optimal pH for the binding capacity of the proteins with cAMP is 4.0, and is shifted to 5.0 in the presence of 5 mM caffeine. The level of bound cAMP increases steeply during 10 minutes of incubation. This is then followed by a less steep increase. The level of bound cAMP decreases in the presence of NaCl. The dissociation onstant between cAMP and the proteins in homogenates of unfertilized and ertilized eggs is about 10 nM, and the value in the embryos at the gastrula stage is lower than that in the unfertilized egg homogenate.
Bovine and hamster zona solutions exhibit receptor activity for capacitated but not for noncapacitated sperm
Authors: Gwatkin R. B. L. , Williams D. T. 
Published: February 2005

AbstractHamster and bovine zonae pellucidae were dissolved by heating them in buffered saline for 35 min at 65°C and 80°C, respectively. Pretreatment of noncapacitated sperm with these solutions did not affect their binding to eggs, but the binding of cumulus‐capacitated hamster sperm and of bovine sperm that had undergone a capacitation‐like surface change in response to hypertonic‐treatment was severely curtailed. These experiments demonstrate that such zona solutions exhibit receptor activity, but only for the capacitated sperm.
Development of a culture medium for growing xenopus laevis oocytes
Authors: Wallace Robin A. , Misulovin Ziva , Jared Donald W. , Wiley H. Steven 
Published: February 2005

AbstractA defined medium for growing defolliculated Xenopus laevis oocytes was developed by monitoring vitellogenin incorporation. Optimum conditions were achieved by use of 50% Liebovitz L‐15 medium supplemented with 1 mM L‐glutamine, 15 mM Hepes, 5 mg/ml vitellogenin, and 1 μg/ml insulin (final pH = 7.8). Stage IV/V oocytes remained morphologically normal in this medium for at least two weeks and grew at an average rate of 0.25 mm3 per week. This is the first time defolliculated Xenopus laevis oocytes have been grown in vitro.
Effect of elevated calcium concentration on fertilization of rat oocytes in vitro
Authors: Kaplan Ruth , Kraicer P. F. 
Published: February 2005

AbstractThe purpose of this study was to develop a modification of the medium of Toyoda and Chang which would permit high rates of fertilization in vitro in rats of our colony. Elevation of the calcium concentration from 1.71 to 3.42 mM increased the fertilization rate by 87%. Greater additions of calcium gave no further improvement. This effect was not due to reduction in phosphate activity, nor was it due to antagonism of heavy‐metal contamination. Although calcium is known to enhance the fertilizing capacity of spermatozoa, our results suggest that it may also affect the oocyte.
Mouse egg penetration is inhibited by Erythrosin B
Authors: Carroll Edward J. , Wolf Don P. 
Published: February 2005

AbstractThe anionic fluorescein dye, Erythrosin B, inhibited the penetration of mouse eggs in vitro. High concentrations of the dye (0.5–1.0 mM) inhibited the penetration of cumulus‐intact, cumulus‐free, and zona‐free eggs at sperm concentrations of approximately 2 × 105 cells per milliliter. Examination of gamete viability indicated that the dye did not cause gross, irreversible changes in either amete, and we therefore concluded that dye‐dependent inhibition may have resulted from dye association with cell membranes. The dye concentration required to give 50% inhibition, apparent I50, of 500 μM obtained for zonafree eggs was artificially elevated by the presence of bovine serum albumin (BSA) (2%) in the culture medium. A corrected I50 of 11 μM was estimated in the absence of BSA.
Inability of exogenous luteinizing hormone to accelerate maturation of oocytes from gonadotrophin‐treated immature rats
Authors: Kaplan Ruth , Kraicer P. F. 
Published: February 2005

AbstractImmature rats, aged 27 days, were stimulated to develop preovulatory follicles by subcutaneous injection of 15 IU of pregnant mare serum gonadotrophin (PMSG). Two days later their oocytes were collected. They were cultured under conditions that permitted continuous observation. Times of the initial stages of maturation were carefully noted, in the absence and the presence of 10 μg/ml of bovine luteinizing hormone (LH). LH did not accelerate germinal vesicle disappearance. It was concluded that the immature PMSG‐treated rat was not an appropriate model for the study of LH action; it was speculated that persistence of PMSG mimicked LH in all the oocytes from such donors.
Localization of zona antigen in bovine ovary sections by fluorescent antibody
Authors: Gwatkin R. B. L. , Meyenhofer M. , Williams D. T. 
Published: February 2005

AbstractTreatment of bovine ovary sections with rabbit antibovine zona serum followed by fluorescein‐conjugated goat antirabbit IgG produced a specific fluorescent staining only of the zonae pellucidae. Fluorescence was greater near the inner and outer surface of the zona, suggesting that either the same antigen occurs in higher concentration in these regions or that there is more than one antigen, the most immunogenic being located peripherally. In some atretic follicles fluorescent material appeared to diffuse into the degenerating oocyte and into the intercellular spaces of the cumulus oophorus.
Cytological effects of urethan on cleavage induction in parthenogenetically activated sea urchin eggs
Authors: Nakashima Seiko , Ishikawa Masaru 
Published: February 2005

AbstractThe effect of urethan on artificial induction of cleavage in eggs of the sea urchin, Hemicentrotus pulcherrimus, was studied. When the eggs were exposed for 20 minutes to seawater containing urethan (final concentration, 0.08 M) after butyric acid‐activation and then treated with hypertonic seawater, the cleavage rate was enchanced by about 1.5 times as compared with the nontreated eggs. In the eggs exposed to urethan–seawater for over 70 minutes many clear spots appeared throughout the cytoplasm. Simultaneously, the pigment granules, which had been embedded within the cortex, migrated to the inner cytoplasm and encircled a monastral centrosphere and clear spots. The clear spots were composed of microtubules much like cytasters, and in the central region of them centrioles were not yet found. The eggs in which the pigment granules disappeared from the cortex may be more susceptible to cleavage induction by succeeding hypertonic treatment.
Reversal of sexual induction in Volvox carteri by ultraviolet irradiation and removal of sexual pheromone
Authors: Kochert Gary , Crump William J. 
Published: February 2005

AbstractWashing in fresh culture medium or short exposure to ultraviolet irradiation (UV) was found to reverse the action of the sexual pheromone produced by the green alga Volvox carteri. Induced gonidia which would normally form egg‐bearing females formed mainly asexual individuals in response to these treatments. The UV effect is strongly dependent on the stage of the life cycle at which exposure is given. Sexual induction in this organism requires early and continuous exposure to the sexual pheromone. The mechanism by which UV reverses sexual induction is not understood, but it could be caused by inactivation of the pheromone or by inactivation of a pheromone‐induced repressor of asexual characters.
Ultrastructural studies of mutant spermatozoids in ferns. I. The mature nonmotile spermatozoid of mutation 230X in Ceratopteris thalictroides(L.)Brongn
Authors: Duckett J. G. , Klekowski E. J. , Hickok L. G. 
Published: February 2005

AbstractElectron microscopy reveals that nonmotility in the spermatozoids of mutant 230X of the fern Ceratopteris thalictroides results from highly aberrant flagella. With respect to its mitochondrial complement, amyloplasts, condensed chromatin within the nucleus and the multilayered structure (MLS), the mutation is almost indistinguishable from the wild‐type spermatozoids. In contrast to flagellar mutations in other organisms (man, mouse, Drosophila, Chlamydomonas), which principally affect the microtubules of the axoneme, the basal body cartwheel is lacking in 230X. In its absence, compound microtubules with shared walls are still present, but in highly disorganized arrays. Since the amount of polymerized tubulin in the spermatozoids of 230X is approximately the same as in the wild type, the mutation does not seem to affect microtubule synthesis or assembly. Centriolar cartwheels appear to be essential templates for the alignment of triplet and doublet tubules in regular radial arrays.The MLS in 230X is almost normal, whereas the flagella are aberrant, indicating that there are two distinct functional classes of microtubules in archegoniate spermatozoids. In contrast to the helix of 3½ gyres found in the wild type, nuclear morphology in 230X exhibits profound distortions ranging from deep channels and holes to supernumerary attenuated arms. Parts of nuclei associated with the MLS are almost normal, but malformations are in variably associated with the presence of microtubules of the aberrant flagella that are in close proximity t o the nuclear surface. The shapes of the teratologies are directly related to the number and configuration of the adjacent perinuclear tubules.From these findings, it is argued that microtubules have a crucial role in nuclear shaping in archegoniates; and that the precise form of the nucleus is closely related to the geometry and development of the MLS. On the other hand, it is difficult to envisage how microtubules growing in the chaotic arrays found in 230X could themselves generate shaping forces, More likely, the actual force‐generating system, situated in or near the nuclear envelope, has become misaligned and severely restricted by the perinuclear arrays of flagellar tubules, which function as cytoskeletal elements additional to those of the normal MLS.Archegoniate plants are particularly advantageous for the detection of basal body mutants, since centrioles are absent from the mitotic apparatus. Cytological and hybridization studies of 230X affirm the nuclear basis of the mutation, and provide no support for the possible genetic autonomy of centrioles.
Quantitation of avian spermatozoan motility: Neurochemical regulation
Authors: Atherton R. W. , Cisson C. M. , Wilson B. W. , Golder T. K. 
Published: February 2005

AbstractThe hypothesis that motility of avian sperm is regulated by acetylcholine was examined by treating rooster (Gallus domesticus) sperm with choline analogs and paraoxon, an inhibitor of colonesterases. Acetylcholine chloride (AChCl) was most effective, acetylthiocholine iodide and butyrylthiocholine iodide were less effective, and choline chloride was ineffective in stimulating sperm motility. Histochemical localization of cholinesterase activity with the electron microscope showed enzyme activity to be associated with membranes of the head and within fibrillar components of the tail. Increasing concentrations of paraoxon decreased cholinesterase activity and increased sperm motility. The data provide evidence that the motility of avian sperm, like that of mammal and sea urchins, may be regulated in part by a system with similarities to the cholinergic neurotransmitter system.
The changes in sperm nuclei after penetrating fish oocytes matured without germinal vesicle material in their cytoplasm
Authors: Iwamatsu T. , Ohta T. 
Published: February 2005

AbstractThe processes occurring from sperm penetration to chromosome formation in the cytoplasm of Oocytes matured in vitro, after removal of the germinal vesicle (GV) and before hormonal stimulation, were observed with electron microscope. The dechorionated oocytes, matured without the participation of the GV material, responded to sperm penetration by initiating a cortical reaction within 20 seconds after insemination. The pentrating sperm nuclei transformed to male pronuclei with vesiculation of the nuclear membrane, chromatin decondensation, and formation of a pronuclear membrane. Before cleavage, however, no chromosome formation was observed in these oocytes. Instead, the fully grown pronuclei change to a picnotic chromatin mass without or with an only fragmented nuclear membrane, then disappeared. On the contrary, sperm nuclei that penetrated into the cytoplasm of naked eggs containing GV material during maturation underwent pronuclear and chromosomal formation. Judging from these observation in Oryzias oocytes, the GV material seems to be unnecessary for the formation of pronucleus from the compact sperm nucleus, but is essential for the process of chromosomal formation.
Ultrastructural studies of spermatogenesis in the anthocerotales. III. Gamete morphogenesis: From spermatogenous cell through midstage spermatid
Authors: Duckett Jeffrey G. , Carothers Zane B. , Moser John W. 
Published: February 2005

AbstractAn ultrastructural examination of spermatogenesis in Phaeoceros has shown nucleoli to be present in spermatogenous cells and to persist until the centrioles become associated with nuclei of young spermatids. At the onset of multilayered structure (MLS) formation, well‐defined aggregations of osmiophilic strands begin to form in the nuclei of young spermatids and disappear shortly after chromatin condensation starts in the midstage spermatids. When the centrioles in the young spermatids are orientated perpendicular to the nuclear envelope, the nucleoplasm immediately in front of them is densely stained. Where the spline tubules of the MLS extend over the nucleus, the nuclear envelope is devoid of pores, and the inner nuclear membrane is contacted internally by the local deposition of dense staining nucleoplasm. Chromatin condensation begins with strands extending perpendicularly from the dense staining nucleoplasm beneath the spline and continues with the nuclear beak becoming filled with condensed chromatin. As the MLS lamellae disappear acropetally, the rear portion of the anterior mitochondrion (AM) extends back under the nuclear beak which now narrows to a size that approximates the anterior end of the nucleus of a spermatozoid. By the end of the mid‐spermatid stage, the nucleus has coiled approximately one gyre of a helix and the five or six central slpine tubules extend over the plastid which is now located beneath the front end of the AM. Several profiles of endoplasmic reticulum confluent with the nuclear envelope are present. Possible factors which might play a role in determining the morphology of the mid‐spermatids are discussed.
Rabbit testis proacrosin: Immunological similarities between testis, sperm proacrosins and the initially formed testis acrosin
Authors: Mukherji Sudhir K. , Scibienski Robert J. , Meizel Stanley 
Published: February 2005

AbstractAnti‐rabbit proacrosin IgG was prepared from goat serum following immunization with a homogeneous preparation of rabbit testis proacrosin. The “auto‐activation” products of purified testis proacrosin were separated into 68,000 and 34,000 molecular weight (mol wt) acrosins by Sephadex G‐100 column chromatography. Immunodiffusion analysis of testis and epididymal sperm proacrosins and acrosins on agarose gel against goat anti‐rabbit testis proacrosin showed immunological identity between rabbit testis and sperm proacrosins and the initial testis acrosin (mol wt 68,000). However, the 34,000 mol wt form of testis acrosin showed weaker reaction with the antibody and only partial identity with the proacrosin and the 68,000 mol wt form of acrosin. These results suggest that there is no major structural difference between testis and sperm proacrosins and between proacrosin and the 68,000 mol wt acrosin, but such a structual change occurs when the 34,000 mol wt acrosin is formed.
Initiation, prolongation, and reactivation of the motility of salmonid spermatozoa
Authors: Benau Danny , Terner Charles 
Published: February 2005

AbstractThe motility of salmonid spermatozoa initiated by dilution of the milt with ovarian fluid or isotonic saline is brief duration; it was believed that it can be activated only once in the life of the spermatozoon. Dilution of the milt with an equal volume of isotonic saline (0.12 M‐NaCl) containing 5 mM‐3‐isobutyl‐1‐methylxanthine (MIX) prolonged and intensified sperm motiliy. When motility had stopped after initial mobilization with saline or ovarian fluid, it could be reactivated by addition of MIX; reactivated spermatozoa fertilized eggs. Dilution with saline containing K+ (24 mEq/liter) did not initiate sperm motility even in the presence of MIX. The spermatozoa were mobilized by subsequent with 0.12 M‐NaCl. The concentration of adenosine triphosphate (ATP) in sperm suspensions dropped on dilution with saline and rose as motility ceased, but declined without subsequent recovery following dilution with MIX‐saline. The concentration of cyclic adenosine monophosphate (cAMP) rose and fell sharply on initiation of motility and rose again after motility had declined. While salmonid spermatozoa can be mobilized by dilition with saline alone, the effectiveness of MIX in reactivating “spent” spermatozoa supports the assumption that cAMP plays a role in the initiation of sperm motility.
Ovoperoxidase activity in ionophore treated mouse eggs. I. Electron microscopic localization
Authors: Gulyas Bela J. , Schmell Eli D. 
Published: February 2005

AbstractA mammalian ovoperoxiadase activity has been detected in ionophore activated mouse eggs. The peroxidase activity was demonstrated at the electron microscopic level using the 3,3′‐diaminobenzidine (DAB) histochemical method. A positive DAB reaction was detected in a portion of the intact cortical granules of untreated or DMSO treated control eggs. In the ionophore activated eggs, the DAB reaction product was routinely detected by electron microscopy, predominantly on the cell surface, that is on the zona pellucida, in the perivitelline space, and in association with the cortical granule exudates. Furthermore, the peroxidase inhibitors phenylhydrazine and sodium sulfite prevented DAB staining in ionophore activated oocytes. These results indicate the presence of an ovoperoxidase, possibly of cortical granule origin, on the surface of activated mammalian eggs, detectable by histochemical means.