bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of 125I‐labeled rat growth hormone in regional brain areas and peripheral tissue of the rat
Authors: Stern Warren C. , Miller Maravene , Resnick Oscar , Morgane Peter J. 
Published: February 2005

AbstractThe uptake of intraperitoneally injected 125I‐labeled rat growth hormone into brain and peripheral tissues was measured in normal and hypophysectomized adult rats. A significant level of radioactivity was observed in the seven brain regions examined – the telencephalon, diencephalon, midbrain, pons‐medulla, cerebellum, pineal and pituitary glands. The pineal and pituitary glands, which are outside the blood‐brain barrier, contained three to four times the concentration of radioactivity of the other brain regions. Compared to brain, the level of radioactivity was much higher in peripheral tissues (the diaphragm, kidney, serum and liver). For example, the serum contained ten times the level of radioactivity of most brain regions. For a given tissue, however, the normal and hypophysectomized rats showed a comparable amount of 125I‐growth hormone. Trichloroacetic acid precipitates from each tissue sample showed that peripheral tissues had a higher proportion of radioactivity (35–48% of total tissue radioactivity) than the brain samples (13–26%). The data support the view that growth hormone, or a metabolite can enter the central nervous system and may directly affect on‐going metabolic processes.
Loss of synapses in the dentate gyrus of the senescent rat
Authors: Bondareff William , Geinisman Yuri 
Published: February 2005

AbstractSynapses were counted in electron micrographs of the middle third of the molecular layer of the dentate gyrus of Fischer 344 rats, 3 months and 25 months of age. A 27% decrease in the number of synapses was found in senescent animals compared with young adults. This loss of synapses could not be correlated with changes in synaptic size, tissue volume or number of postsynaptic granule cells.
An angiographic study of the carotid arterial and jugular venous systems in the cat
Authors: Kumar A. J. , Hochwald G. M. , Kricheff I. 
Published: February 2005

AbstractStandard techniques for performing carotid angiography in dogs and in man were adapted to the cat in order to study the vascularization of both intracranial and extracranial structures. Venous drainage was examined by venography of selected vessels. The carotid‐cerebral and the vertebral‐basilar arterial systems of the cat were studied, although no attempt was made to define the territory supplied by each system.In serial angiograms, vascularization of the rete mirabile conjugatum was visualized, and distinct arterial and venous retia were delineated. Large facial veins were seen approximately one second after the intra‐arterial injection of radio‐contrast material. The early filling of the large facial veins appeared to be the result of an artery‐to‐venous shunt. Contrast material flowed posteriorly in these veins and drained into the venous rete. When contrast material was injected either into the sagittal sinus or retrograde in the external jugular vein, the internal jugular vein was visible in four of ten cats. This vessel drained blood directly from intracranial contents before anastomosis with the vertebral and external jugular veins.
Immunological competence in Snell‐Bagg pituitary dwarf mice: Response to the contact‐sensitizing agent oxazolone
Authors: Schneider Gary B. 
Published: February 2005

AbstractSnell‐Bagg pituitary dwarf mice are an autosomal recessive mutant, their dwarfism being the result of an anterior pituitary defect. A number of investigators have reported that these mice, in addition to having hormonal deficiencies, have immunological defects. Dwarf mice reject allogenic skin grafts slowly, show a reduced response to contact agents and decreased graft‐vs.‐host reactivity. Other investigators have suggested that these results indicate a thymus‐cell‐deficiency. Contrary to this conclusion, we have found that the thymuses in our dwarf mice have a normal cellular composition and the T‐cell‐dependent zones in the peripheral lymphoid tissues are not deficient in lymphocytes. Therefore, this investigation was undertaken to study the response of dwarf mice to the hapten, oxazolone, which produces one type of T‐cell‐dependent response, delayed hypersensitivity, and to compare this response to that of normal littermates in animals 15 to 90 days of age.The results of these studies indicate that the dwarf mice have the ability to develop delayed hypersensitivity, as shown by both a blastogenic response in the lymph node draining the site of sensitization (the induction phase of delayed hypersensitivity) and by a positive skin‐test. The magnitudes of the blastogenic response and the skin‐test reaction appear similar in dwarf and normal littermate animals, both histologically, and quantitatively. These results, which are in contrast to other studies, may be the result of the husbandry provided our colony of dwarf mice, and the immunological deficiencies that have been described previously may not be a necessary condition accompanying dwarfism in these mice.
Cytological development of yolk sac endoderm and protein‐absorptive mesothelium in the little brown bat, Myotis lucifugus
Authors: Enders Allen C. , Wimsatt William A. , King Barry F. 
Published: February 2005

AbstractThe yolk sac of the little brown bat is unusual in that during the course of gestation both the inner endodermal cells (bordering the yolk sac cavity) and outer mesothelium (facing the exocelom) form simple columnar epithelia which persist throughout gestation. These endodermal cells develop an extensive system of agranular endoplasmic reticulum, numerous lipid droplets and unusual “giant” mitochondria. During development the Golgi apparatus changes position from the apical to the basal side of the nucleus, reversing the polarity of the cells. In general, the endodermal cells have cytological features suggestive of synthetic or secretory activity. The mesothelial cells develop an extensive “absorptive apparatus” in their apices, while large crystalloid‐containing granules become numerous in their basal cytoplasm. The mesothelial cells have large deposits of glycogen, especially during mid‐gestation, but few mitochondria and little granular endoplasmic reticulum. Endodermal cells do not absorb exogenous protein (peroxidase) even if it is injected directly into the yolk sac cavity. However, placement of peroxidase either in the exocelom or in the maternal vascular system results in the appearance of this protein in the “absorptive apparatus” of mesothelial cells as well as in macrophages in the stroma of the yolk sac. While evidence of absorption was clear, no direct evidence of transport of tracer to fetal blood vascular system was obtained. It is postulated that a major function of the hypertrophied mesothelial cells during gestation is the absorption of proteins and possibly other substances from the exocelomic fluid. The major function of the hypertrophied endodermal cells may be synthesis and secretion of substances into the fetal circulation.
Comparative histochemistry of gastrointestinal mucosubstances
Authors: Sheahan Daniel G. , Jervis Helen R. 
Published: February 2005

AbstractTwo histochemical sequential staining techniques, Alcian blue‐PAS (AB‐PAS) and high‐iron‐diamine‐Alcian blue (HID‐AB), which differentiate neutral from sulfated and non‐sulfated acid mucosubstances, were applied to sections from the gastrointestinal tract of eleven mammalian species, including man, to study patterns of distribution of gastrointestinal epithelial mucosubstances. The application of these techniques under uniform laboratory conditions enabled a detailed description of epithelial mucosubstances throughout the gastrointestinal tract relative to location in each species as well as a comparison of their distribution among various species.The results showed that all of the 11 species studied had a distinctly different distribution of epithelial mucosubstances throughout the entire gastrointestinal tract. These differences were most obvious in the stomach and duodenum. In each species, neutral mucosubstances were most evident in the stomach and acid mucosubstances in the intestines, with sulfomucins most prominent in the large bowel. Acid mucosubstances were noted in Paneth cell granules of rodent species only. These histochemical observations make available a uniform comparative basis for the normal distribution of mammalian gastrointestinal mucosubstances which should facilitate their study in diverse pathological conditions.
Postnatal development of acinar cells in rat submandibular gland as revealed by electron microscopic staining for carbohydrates
Authors: Yamashina Shohei , Mizuhira Vinci 
Published: February 2005

AbstractThe postnatal differentiation of acinar cells in rat submandibular gland was studied by staining with periodic acid‐thiosemicarbazide‐silver proteinate to identify carbohydrate‐containing macromolecules in the electron microscope. This method revealed glycogen particles and internal substructure in the secretory granules of developing acinar cells. On the basis of morphologic and histochemical criteria three phases of acinar cell development were defined. In the pro‐acinar phase, during the first week after birth, pro‐acinar cells and terminal tubular cells were the main components of the terminal tubules in the rudimentary gland. The secretory granules of the pro‐acinar cells contained speckled or rod‐like substructures which stained intensively for carbohydrates and were digested by proteolytic enzymes. During the second to third week after birth, which is the immature‐acinar‐cell phase, thread‐like substructures were seen in the secretory granules. These structures, which were not digested by proteolytic enzymes, disappeared gradually. The acinar cells of 4‐week‐old or older rats displayed no particular substructure in the secretion granules and represented the final, mature phase of development.
Extra‐ and intra‐cranial blood supply to brains of dog and cat
Authors: Gillilan Lois A. 
Published: February 2005

AbstractThe dog and cat are useful experimental animals, and information regarding their cerebrovascular patterns and the source of blood supplying their brains is important. Blood vessels to brains and heads of cats and dogs were injected with various contrast media. Extracranial and intracranial arteries were studied grossly and in cleared sections.The proximal part of the internal carotid artery is small in the dog and nonfunctional in the cat. The largest single source of arterial blood supplying the brains of these species comes from the maxillary artery over an anastomotic ramus leading to an internal rete mirabile enmeshed in the cavernous sinus. The distal segment of the internal carotid arises from this anastomosis. The brainstem of both animals is supplied by C1 branches of the vertebral arteries, and in the dog an occipital ramus makes a large contribution to it. In addition to an internal rete mirabile, the cat possesses a large external rete mirabile surrounding the maxillary artery and giving rise to all branches in the area. It is functionally equivalent to the ramus anastomoticus in the dog.Arterial patterns over brains of Carnivora are similar. They resemble those of lower mammals more than those of primates. Extensive extracranial arterial anastomoses located in the orbit, retia mirabilia and neck musculature are significant and make it difficult to render the brains ischemic.
Intranuclear bodies in neurons of the periaqueductal gray matter in the cat
Authors: Liu Rita P. C. , Hamilton Betty L. 
Published: February 2005

AbstractThe nucleoplasm of neurons in the nucleus lateralis of the periaqueductal gray matter in the cat contains fibrillar structures which have no limiting membranes. These intranuclear bodies are associated with neither the nucleolus nor the nuclear membrane and have two characteristic forms. The first, the rodlet, is a compact bundle of fibrils 2 to 8 nm in diameter. It is usually elongated in shape although it appears spherical when sectioned transversely. This rodlike structure appears to correspond to Roncoroni's rodlet or the accessory body of Cajal in light microscopy. The second and more commonly observed form is a long slender bundle of five rows of parallel fibrils. Although similar intranuclear structures have frequently been observed in the highly differentiated neurons of the sympathetic ganglia and the retina, this is the first report of their presence in the undifferentiated neurons of the isodendritic core of the brainstem.
Cholinergic innervation of the simian oxyntic gastric mucosa
Authors: Lechago Juan , Barajas Luciano 
Published: February 2005

AbstractThe innervation of the oxyntic gastric mucosa was studied by light and electron microscopy in the rhesus monkey. An abundant net of acetylcholinesterase‐positive nerves was seen in the lamina propria, with many slender fibers noted close to the basal lamina of the glands. Electron microscopic observation disclosed the presence of nerve fibers containing axons and varicosities in the lamina propria, often in very close proximity to the epithelial glandular cells. Nerve endings partly enveloped by a Schwann cell were occasionally seen in direct contact with a parietal cell.
Ultrastructural observations on rabbit, hamster and mouse eggs following electrical stimulation in vitro
Authors: Gulyas Bela J. 
Published: February 2005

AbstractThe fine structural changes were studied in the plasma membrane, cortical granules (CGs) and meiotic spindle of rabbit, hamster and mouse eggs in response to electrical stimulation. Eggs were collected 16 to 18 hours after HCG injection, and freed from the cumulus oophorus. They were stimulated in vitro by delivering a single monophasic square wave pulse of 150 V for 1 msec. Stimulated and unstimulated eggs were fixed for fine structural observations 1, 30 and 60 minutes after stimulation. Within one minute of stimulation the microvilli of rabbit eggs were long, branching and had bulbous ends. Umbonate protrusions were also present on their surface. By 30 minutes after stimulation the rabbit eggs lacked microvilli and the perivitelline space was filled with detached vesicles. Degenerating changes were readily noticeable in the microvilli of hamster eggs by 60 minutes. Changes were not noted in the microvilli of stimulated mouse eggs. There were markedly fewer CGs in the hamster and mouse, but not rabbit, eggs by 30 minutes after stimulation, and nearly all of them disappeared in the mouse and hamster eggs by 60 minutes. The density of the CGs in the rabbit was not altered. The meiotic spindle of hamster eggs dissipated within one minute of stimulation, however, the microtubules reappeared by 60 minutes after stimulation. Rotation of the meiotic spindle occurred in the mouse and hamster eggs by 30 minutes after stimulation. In some of the mouse eggs the spindle migrated to the center and the chromosomes were in telophase.
Tight and gap junctions in a vertebrate inner ear
Authors: Nadol Joseph B. , Mulroy Michael J. , Goodenough Daniel A. , Weiss Thomas F. 
Published: February 2005

AbstractThe auditory organ of the alligator lizard has been investigated with the transmission electron microscope using methods which distinguish between tight and gap junctions. There is a continuous zone of tight junctions located near the endolymphatic surface of the organ forming a boundary between the endolymph in scala media and the interstitial spaces between the cells. No such tight junctions were observed between the perilymph of scala tympani and the interstitial fluid within the organ. Small gap junctions occur between hair cells and supporting cells and large gap junctions occur between adjacent supporting cells. The locations of the tight junctions suggest that the composition of the intercellular fluid in the receptor organ is probably more like perilymph than like endolymph. The presence of gap junctions between hair cells and supporting cells provides a possible morphological basis for the occurrence of intracellular responses to sound in supporting cells, and for electric coupling of receptor cells.
The histological structure of dog knee menisci with comments on its possible significance
Authors: O'Connor Brian L. 
Published: February 2005

AbstractKnee‐joint menisci are poorly understood terminologically, structurally and functionally in spite of their almost universal occurrence in mammals and their considerable clinical significance in man. A study was therefore undertaken of dog knee menisci utilizing several histological techniques.Terminologically, it is proposed that the part of the meniscus extending between the anterior and posterior horns and exclusive of them be called the meniscal “body.”Structurally, the horns and body differ in a number of ways. The horns are oval in cross section, the body triangular. Hyalinized areas are much more frequent in the body than in the horns. The collagen of the horns is organized into discrete bundles that are separated from one another by loose connective tissue septa, while that of the body is arranged in a “herringbone” pattern; no septa are present in the body. Finally, the meniscal horns are richly supplied with blood vessels and nerves (including large myelinated fibers which apparently terminate in the horns) while the body is almost completely devoid of blood vessels and nerves.Functionally, it is hypothesized that knee‐joint menisci may serve important sensory functions.
Development of the octopus cell area in the cat ventral cochlear nucleus
Authors: Schwartz Ann Marie , Kane Eileen S. 
Published: February 2005

AbstractThe octopus cell area (OCA) of the posteroventral cochlear nucleus was studied electron microscopically in kittens. The adult OCA, a region of morphologically homogenous neurons receiving heterotypic synapses from the cochlea, was used to define the mature state. The OCA reaches cytological maturity at three weeks postnatally, after progression through four stages, defined on the basis of octopus cell cytology (including relative numbers of somatic and dendritic filopodia and spines) and the frequency, ultrastructure and location of previously defined synaptic terminals. Octopus cell size was also studied in rapid Golgi impregnations. The OCA from birth through three postnatal days (stage 1) showed small neurons, few identifiable synaptic types, small, mostly unmyelinated axons, mitotic cells and undifferentiated glia. Between the fourth and seventh postnatal days (stage 2) distinct type 1 and type 2 endings appeared and dendrites thickened, expanded peripherally and developed mature spines. During stage 3 (8–19 days) loss of filopodia, increased somatic spicules, larger somas and clearer differentiation of type 1 and type 2 synapses occurred. After three postnatal weeks (stage 4) the OCA contained morphologically mature octopus cell somas, all three synaptic types ending upon somas and thick basal dendrites, and fascicles of myelinated fibers. Although cytologically mature, the OCA at this stage (about 20–35 days) is substantially smaller than the adult OCA. This smaller size will facilitate further study of OCA synaptic organization.
Disposition of 14C‐nicotine in the fertilized chick egg
Authors: Di Carlo Frederick J. , Gilani Shamshad H. 
Published: February 2005

Abstract14C‐Nicotine·HCl (4.5 mg) was injected into the air space of chick eggs after one day of incubation and the distribution of radioactivity measured on days 3, 5, 7 and 12. By day 3, 98% of the dose had passed from the air space into the egg, proper. The quantity of nicotine in the yolk was highest on day 3 (74% of dose) and decreased steadily until day 12 (52%). The quantity in the albumen increased from 16% on day 3 to a maximum on day 7 and remained constant at 34% until day 12. The embryo contained 0.03% of the nicotine on day 3, and this level increased to 5% by day 12. Nicotine in the allantois increased throughout the study period (0.01% on day 3 to 3% on day 12). Although only 5% of the dose was present in the embryo, the highest concentrations of nicotine observed were in the heart, liver and carcass. The concentrations within these components of the embryo ranged from a minimum of 0.85 μg nicotine/mg dry wt in the heart to a maximum of 2.00 μg nicotine/mg dry wt in the carcass. These levels within the embryo were two to five times higher than the greatest concentrations in the yolk and albumen. The dynamics of nicotine passage from the air space into other components of the fertilized chick egg were clarified. Whereas the conventional expression of teratogenic doses of drugs in chick eggs (i.e., ppm of egg weight) assumes that the compound is distributed uniformaly, this study indicates that such expressions are inaccurate.
Ultrastructure of pericytes in mouse heart
Authors: Forbes M. S. , Rennels M. L. , Nelson E. 
Published: February 2005

AbstractThe pericytes of mouse myocardium are extensively branched cells that forma an incomplete layer around the endothelium of capillaries and postcapillary venules. The membranes of pericytes and endothelial cells are conected by specialized junctions. Microtubules, intermediate (10‐nm) filaments and microfilaments are oriented within circumferentially‐arranged cytoplasmic processes of pericytes so as partially to encircle the endothelial cylinder. The intracellular organization of these myocardial pericytes suggests that they are smoth muscle‐like cells which may be capable of influencing microvascular dynamics in the heart.
Movement of the hyoid in frogs during feeding
Authors: Emerson Sharon B. 
Published: February 2005

AbstractFeeding, breathing, and vocalization sequences of Bufo marinus were recorded by cineradiography. Results of film analysis indicate that the hyoid moves during all three behaviors. Movement of the hyoid is critical in tongue protrusion of frogs, and a biomechanical model of this action is presented. The hyoid appears to represent a compromise morphological system for three functions, rather than an optimal system for any one. This may explain, in part, the retention of a relatively inefficient breathing mechanism in frogs.
The predominance of binucleation in isolated rat heart myocytes
Authors: Katzberg Allen A. , Farmer Barbara B. , Harris Robert A. 
Published: February 2005

AbstractMyocytes of the heart of the newborn rat are mononucleated, whereas myocytes of the heart of growing, maturing rats become predominantly binucleated. This appears to be explained by mitotic division shortly after birth without cell division, i.e., karyokinesis without cytokinesis. Myocytes isolated from hearts of adult guinea pig and pigeon are also predominantly binucleated. Although only about an eighth of the cells of adult rat hearts are myocytes, most of the increase in size of the heart from birth to six months can be accounted for by change in size of these cells.