bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early responses of testicular interstitial cells to stimulation by interstitial‐cell‐stimulating hormone
Authors: Aoki Agustin , Massa Eddy M. 
Published: February 2005

AbstractThe fine structure of testicular interstitial cells from mice submitted to different experimental conditions is described. Following treatment with methallibure (I.C.I. 33,828; 1‐α‐methylallylthiocarbamoyl‐2‐methylthiocarbamoylhydrazine), a selective inhibitor of hypophyseal gonadotropic activity, interstitial cells acquire a quiescent appearance characterized by: (1) accentuated segregation of agranular endoplasmic reticulum from other cytoplasmic organelles and inclusions, (2) increased depots of lipid droplets. A single injection of interstitial‐cell‐stimulating hormone (ICSH or LH) induces prominent changes in the ultrastructure and distribution of cell inclusions and organelles that are seemingly related to augmented secretory activity. The cell surface shows a striking development of cytoplasmic processes that interdigitate with similar processes from adjacent cells. Intercellular spaces form a system of interfacial channels providing a direct connection of the interstitial cell surface with blood vessels and the myoid layer of seminiferous tubules. Gonadotropic stimulation causes an increased number of free ribosomes and expansion of the Golgi complex and rough endoplasmic reticulum. There is a marked depletion of lipid droplets and formation of lipofuscin granules.
Ultrastructure of cardiac muscle from dystrophic mice
Authors: Forbes M. S. , Sperelakis N. 
Published: February 2005

AbstractThe ultrastructure of cardiac muscle from dystrophic mice was compared with that of their non‐dystrophic littermates. Among the abnormalities observed in the fine structure of the muscle fibers in the dystrophic animals were increased lipid, swollen mitochondria, swollen tubules of the sarcoplasmic reticulum, supercontracted myofibrils, and partially separated intercalated discs. The ventricular muscle appeared to be the region most often affected; in only one of eleven animals did the atrium show discernible effects of the dystrophy. Although a progression of degenerative events seemed to occur, a time schedule could not be determined because of the large variation among hearts of dystrophic animals. The ultrastructure of the hearts from non‐dystrophic littermates was normal. It appears that the depressed cardiac function caused by the myopathy may play a major role in the early death of the dystrophic mice, as in the case of dystrophic hamsters and men. Most of the ultrastructural abnormalities observed could be accounted for if there were an elevation of intracellular free Ca++ concentration.
Simultaneous demonstration of catecholamines and acetylcholinesterase in peripheral autonomic nerves
Authors: Ellison Jeffrey P. , Olander Kenneth W. 
Published: February 2005

AbstractCertain primary catecholamines remain well localized during brief fixation with cold, buffered formalin. In the present study, the diffusibility of catecholamines was further explored, using guinea‐pigs and cats pretreated with Nialamide and norepinephrine. Preliminary experiments showed that catecholamines were well localized after perfusion fixation with buffered formalin. Furthermore, catecholamines remained in situ in tissues immersed in cold fixative or phosphate buffer for as long as six hours. It seemed, therefore, that catecholamines might remain localized in fixed tissue, during incubation for acetylcholinesterase. To test this hypothesis, formaldehyde‐fixed, cryostat sections were incubated in a cold thiocholine medium for two to four hours to demonstrate acetylcholinesterase activity. They were then exposed to formaldehyde gas to demonstrate catecholamines. Acetylcholinesterase‐positive and catecholaminecontaining nerve fibers were identified simultaneously in the same section under mixed ultraviolet and red light. When a dark‐field condenser was used, adrenergic nerves appeared green and acetylcholinesterase‐positive nerves red on a black background. We were able to demonstrate adrenergic presynaptic terminals on cholinergic myenteric ganglion cells and acetylcholinesterase‐positive terminals close to cardiac chromaffin cells. We also have observed contiguities between peripheral adrenergic and cholinesterase‐positive nerves.
Intranuclear inclusions in mammotrophs of the female mongolian gerbil
Authors: Nakayama Iwao , Nickerson Peter A. 
Published: February 2005

AbstractMembranous and vacuolar inclusions have been identified within the nucleus of mammotrophs in the pituitary of female Mongolian gerbils but are absent in adult male and newborn gerbils of both sexes. Membranous inclusions are observed in focal areas of the nucleus and are frequently in proximity to the inner nuclear membrane. Vacuoles are surrounded by a single membrane and the matrix is structureless and either flocculent or clear. An intermediate form of nuclear inclusion is membrane‐bound and contains typical cytoplasmic organelles. It is suggested that degenerative changes in inclusions originating in the cytoplasm may produce large structureless vacuoles. The increased number of inclusions in testosterone‐treated animals may be a response of mammotrophs to alteration in synthesis or release of hormone.
Projections of adrenocortical cells into sinusoidal lumina. Influence of prostaglandin E1
Authors: Penney D. P. , Averill K. , Olson J. 
Published: February 2005

AbstractCytoplasmic projections of adrenocortical cells have been observed within sinusoidal lumina of various species. The projections contain organelles and inclusions which are morphologically identical to those in subjacent functional cortical cells, and appear to be capable of hormone biosynthesis. The frequency with which the projections are observed is markedly enhanced by the administration of prostaglandin E1. Continuity has been observed between the projections and the parenchymal cells. Whether or not these morphological entities reflect a mechanism for an enhanced response to corticotropin stimulation remains uncertain. Their association with cellular autolysis or degradation appears doubtful.
Evidence for spontaneous axon degeneration during peripheral nerve maturation
Authors: Reier Paul J. , Hughes Arthur 
Published: February 2005

AbstractUltrastructural examination of sciatic nerves from postnatal mice and rats revealed myelinated and nonmyelinated fibers with structural characteristics similar to those seen in Wallerian degeneration. Such fibers are more commonly found between 7 and 14 days and are believed to represent spontaneous axon degenerations during development.
Anatomical nomenclature 1972
Authors: Zwemer Raymund L. 
Published: February 2005

AbstractAnatomists have led the way for 75 years in developing internationally acceptable terminology for macroscopic structures of the human body. During the past 12 years terms have been gathered for histology and embryology. Nomenclature in all three areas have been adopted for international use by the Fifth to Ninth International Congresses of Anatomists. Cooperation with biomedical and other scientists will promote better communication and understanding now and provide a useful tool for future science information systems. Embryologists, histologists and gross anatomists can be proud of their current accomplishments, but should continue to work diligently to incorporate new terms as they become generally acceptable.
Serum triiodothyronine concentration in the iodine‐deficient rat
Authors: Volpert Eugene M. , Werner Sidney C. 
Published: February 2005

AbstractA low iodine diet fed to rats resulted in decreased absolute amounts of circulating triiodothyronine and protein‐bound iodine (PBI), but an increase in the triiodothyronine: protein‐bound iodine ratio. Since baseline protein‐bound iodine values were high, it is possible the “normal” diet fed was in fact a high iodine one. In this event, the fall in protein‐bound iodine with the low iodine diet would be greater than that in thyroxine concentration. The relative increase in triiodothyronine compared to PBI concentration with the low iodine diet could result from preforential synthesis and secretion of triiodothyronine by the iodine‐deficient thyroid; or could be due to accelerated removal of thyroxine due to increased peripheral utilization. Either change could keep body metabolism normal or nearly so over an extended period of iodine want.
Inhibitory effect of hysterectomy on compensatory ovulation in the unilaterally ovariectomized rat
Authors: Peppler Richard D. 
Published: February 2005

AbstractCyclic rats were hysterectomized and unilaterally ovariectomized during random stages of the cycle or on day 2 (metestrus) and killed in metestrus after one or two complete estrous cycles. Control (intact and unilaterally ovariectomized) rats were also killed at this time.Counts of tubal ova revealed that intact rats ovulated an average of 4.9 eggs per ovary (N‐5). Following only unilateral ovariectomy, compensatory ovulation (10.1 eggs per ovary) occurred in all rats (N‐6). However, when both hemicastration and hysterectomy were performed, only 6.5 eggs were shed (N‐19). The findings suggest an inhibitory effect of hysterectomy on compensatory ovulation in the unilaterally ovariectomized rat.
Ultrastructure of the human submaxillary gland IV. Serous granules
Authors: Tandler Bernard , Erlandson Robert A. 
Published: February 2005

AbstractAcinar serous granules in specimens of human submaxillary gland fixed with aldehydes followed by osmium were examined in the electron microscope. Typical mature granules had a tripartite substructure: (1) an eccentrically placed dense spherule; (2) material of intermediate density adherent to the inner aspect of the granule membrane in the form of a crescent; and (3) a less dense, homogeneously fibrillo‐granular matrix. The dense spherules appeared within expanded Golgi saccules; other granule constituents apparently were of secondary acquisition. A few cells contained atypical serous granules in which material of intermediate density was disposed in random loops, whorls, and striae. Such granules usually lacked dense spherules. It is postulated that the two morphologically distinct types of granules represent separate classes of serous secretory products.
Light and electron microscopic observations on the morphogenesis of the chorioallantoic placenta of the golden hamster (Cricetus auratus). Days seven through nine of gestation
Authors: Carpenter Stanley J. 
Published: February 2005

AbstractIn the mature placental labyrinth of common myomorph rodents (rat, mouse and hamster) fetal capillaries are separated from maternal blood spaces by trabeculae composed of three distinct cytoplasmic layers. To resolve the controversy regarding the embryonic origin(s) of these layers a correlated light and electron microscopic study was made of the developing placental tissues of the golden hamster during the eighth and ninth days of gestation, the critical period of labyrinth morphogenesis in this species. It was determined that the syncytial inner layer (layer III) of the trabeculae, the layer bordering the fetal capillaries, is derived from the “true” chorionic ectoderm which fuses with the undersurface of the Träger (ectoplacental cone) early on the eighth day of gestation. Both the syncytial middle layer (layer II) and the cellular outer layer (layerI) of the trabeculae, on the other hand, were found to differentiate from the trophoblastic cells of the Träger. Allantoic mesenchyme, which approximates the fused chorionic‐Träger tissues late on day eight and is the source of the fetal capillaries and mesenchyme of the labyrinth, was noted to exert a critical inductive effect on the morphogenesis of syncytial layers II and III. On the basis of fine structure, the developing labyrinth appears not to be a major site for maternal‐fetal transfer of macromolecules nor to be involved to a significant degree in the production of proteins or steroids for secretion.
Intercellular connective tissue fibrils in the notochordal epithelium of the early chick embryo
Authors: Carlson Edward C. 
Published: February 2005

AbstractChick embryos of the White Leghorn strain were incubated from one‐half to four days and sacrificed by immersion in toto. in Karnovsky's fixative. The cervical region of each embryo was excised and prepared for electron microscopy. Intercellular materials, which appear indistinguishable from the early connective tissue components of the embryonic tissue space, appear within dilated interstices of the notochordal epithelium beginning at approximately Hamburger‐Hamilton stage 14. At progressively older stages this intercellular material appears to organize and aggregate to form fibrils. By stage 22 widely expanded intercellular spaces contain boundary (basement) membrane material, amorphous substance and microfibrils of various sizes. Moreover, larger, more mature fibrils that exhibit collagen‐like periodic striations are present. The existence of connective tissue materials in cellular interstices deep within the central portion of the notochord strongly suggests that these substances are derived from notochordal epithelial cells. Furthermore, the similarity of the intercellular connective tissue components to those deposited on the notochordal surface suggests that these latter materials are likewise a secretory product of the notochord. The significance of the perinotochordal connective tissue (notochord sheath) with respect to the recent emphasis on the role of surface‐associated substances to cytodifferentiation is discussed.
Presence of biogenic amines in early rat development
Authors: Burden Hubert W. , Lawrence Irvin E. 
Published: February 2005

AbstractRat ova, zygotes, and (2‐ to 4‐cell) embryos were processed for the fluorescence demonstration of catecholamines and serotonin. Specific endogenous fluorescence, characteristic of catecholamines, was observed in all stages studied. The endogenous fluorescence was intensified by incubation in serotonin or norepinephrine. These observations suggest a role for biogenic amines in early mammalian cleavage, similar to that previously reported in invertebrates.
Morphometric and electron microscopic studies of goiter induced by lithium in the rat
Authors: Heltne Carl E. , Ollerich Dwayne A. 
Published: February 2005

AbstractFifty‐two male and female albino rats were used. Lithium‐treated rats (30 animals) received twice daily intraperitoneal injections of lithium carbonate (40 mg/kg body weight) for 80 days. Three control groups were used. The first remained uninjected; the second received sodium chloride solution equal in volume and tonicity to the lithium carbonate solution; the third received sodium carbonate solution in which the carbonate ion concentration was equivalent to that in the lithium carbonate solution. Thyroid weights were analyzed as wet and dry weights, and as wet and dry thyroid weights in milligrams per 100 gm body weight. Morphometric or electron microscopic studies were carried out on Epon‐embedded tissue routinely prepared for light or electron microscopy.Thyroid weights and values were greater in lithium‐treated animals. A sex‐related effect of lithium was indicated. The differences in thyroid weights between lithium‐treated and control male rats were greater than those between female lithium‐treated and control rats. Morphometric analysis revealed an increase in the mean diameter of sections of follicles and relative amounts of colloid, and a decrease in follicular cell heights in lithium‐treated animals. The electron microscope revealed an enlarged Golgi apparatus in many thyroid follicular cells of lithium‐treated rats. The enlargement of the Golgi apparatus was most evident in male lithium‐treated animals. The relationship of these findings to the mechanism of lithium action was briefly discussed.
The development of the primary vascular reticulum in the spleen of human fetuses (38‐ to 57‐mm crown‐rump length)
Authors: Weiss Leon 
Published: February 2005

AbstractThe development of the primary vascular reticulum and of the capsule was studied electron microscopically in spleens from five human fetuses measuring 38, 42, 43, 50 and 57 mm in crown‐rump length (CRL).The reticulum developed progressively. At 38 mm CRL reticular cells had short broad processes and the interstitium was quite limited. The reticulum continued to open with advancing age until, in the 57‐mm fetus, reticular cells had long slender processes and formed a reticulum with voluminous interstices. Contiguous cells were attached by junctional complexes of the intermediate type (zonula adherens). The salient cytological features of reticular cells were vacuoles, ribosomes, and rough endoplasmic reticulum. An argyrophilic reticulum was present which, unlike the adult extracellular reticulum, was not closely associated with reticular cells and was composed, in certain sites, primarily of collagen.A rich vasculature of closed thin‐walled loops was present in the 38‐mm fetus. Thereafter, an open vascular pattern, most pronounced in the 50‐ and 57‐mm CRL fetuses, was observed. Blood and macrophages lay in the interstices of the reticular meshwork and active vasculogenesis with marked differentiation into arteries, capillaries, veins, and vascular sinuses occurred. Endothelial cells were joined by junctional complexes of the intermediate type. The vessels lacked basal laminae or basement membranes. No evidence of significant hematopoiesis was observed.The capsule consisted of a simple layer of irregularly cuboidal cells having microvilli and cilia on the peritoneal surface, desmosomes and intermediate junctions on their lateral surfaces, cytoplasmic vacuoles, glycogen, fat, ribosomes, and rough endoplasmic reticulum, intercellular and infracellular spaces; the capsule rested on a well‐defined basal lamina.Thus, a primary vascular reticulum developed and comprised the splenic pulp. Though of simple form, it accomplished the fundamental function of the spleen: a filter and modifier of blood.
The fine structure of the pineal gland in the pocket gopher, Geomys bursarius
Authors: Sheridan Michael N. , Reiter Russel J. 
Published: February 2005

AbstractThe morphology of the pineal gland of the pocket gopher, Geomys bursarius, is of special interest because this species is exposed to extremes of environmental lighting in its natural habitat. The pineal gland of the gopher has been studied in specimens collected as they were about to enter their winter dormant period.The gopher pineal is similar to other mammalian pineal glands in that it possesses light and dark parenchymal cells, glia, and pigment‐containing‐cells. Vascular‐parenchymal relationships are similar to other species.Vesicles containing electron‐opaque cores are infrequently encountered in the parenchymal cells. Parenchymal cells and pigment cells occasionally abut a lumen, suggesting an acinar arrangement. Large cytoplasmic vacuoles several microns in diameter are present in the parenchymal cells.
Unusual mitochondrial morphology in the rat adrenal cortex following hypophysectomy
Authors: Sharawy M. , Penney D. P. 
Published: February 2005

AbstractUnusually long and thin mitochondria (3–4 μ in length and 0.2–0.4 μ in width) were observed in zona fasciculata cells in the hypophysectomized rat adrenal cortex. The elongated mitochondria assumed C‐shape configurations and were frequently in juxtaposition to each other and to lipid droplets. These mitochondrial organizations were considered to be unstable, dependent on the presence of trophic hormone and involved in the formation of bizarre membranous bodies. The relationship of these observations to the process of glandular involution is discussed.
The vascular anatomy of the liver of the monitor lizard (genus varanus)
Authors: Yeager Vernon L. 
Published: February 2005

AbstractThe gross and microscopic anatomy of the vasculature of the monitor lizard liver was studied. The portal vein has a peculiar arrangement of smooth muscle. The tunical media of the entering portal vein has bundles of smooth muscle cells separated by large numbers of collagenous fibers. The amount of smooth muscle decreases as the vessel decreases in diameter and soon one finds intermittent broad, thin bands of smooth muscle. As the caliber of the vessels continues to decrease, the smooth muscle bands become narrower and thicker so that they appear as doughnut‐shaped sphincters. The sphincters are usually found at the beginning of each branch of the portal vein as well as along the course of veins between areas of branching. Some sphincters are found in direct contact with the outer capsule of the liver. Sphincters occur in the terminal branches of the portal vein just proximal to the sinusoids.Small numbers of scattered smooth muscle cells were seen arranged longitudinally, obliquely, or circularly in the smaller hepatic veins. Even the large hepatic veins had only small amounts of smooth muscle. At no place along the course of hepatic veins could smooth muscle sphincters equivalent to those seen around portal veins be found.The monitor lizard should be an excellent subject for physiological and pharmacological studies of regulation of intrahepatic portal vein blood flow.
Differentiation of alpha cells in the fetal rat pancreas grown in organ culture
Authors: Schweisthal Michael R. , Frost Cecil C. 
Published: February 2005

AbstractAlpha cells can be demonstrated in embryonic rat pancreas by a modification of the Grimelius silver nitrate technique. At the start of culture at 18 days of gestation, alpha cells are closely associated with exocrine tubules and beta cells. After ten days of culture they are arranged peripherally around a mass of beta cells, in islets that are characteristic of adult rat pancreas.