bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on the structure of the eumelanosome matrix in melanosomes of the chick retinal pigment epithelium
Authors: Zimmerman J. , Winfrey F. , Good P. 
Published: February 2005

AbstractEumelanosomes from the developing chick pigment epithelium have been isolated, solubilized, and the residue collected. Examination of this material in the electron microscope provides evidence for new structural entities in the eumelanosome and information on the organization of the melanosome. This evidence suggests that there are (1) 190‐Å fibers arranged in a zigzag fashion, surrounding 240‐Å–diameter electron‐lucent spaces and (2) an internal gridwork enclosing 40–50‐Å‐diameter spaces. These two structures are probably alternately layered and “rolled‐up.”
Embryonic development of the rat pineal gland
Authors: Calvo J. , Boya J. 
Published: February 2005

AbstractThe embryonic development of the albino rat pineal gland has been studied from day 13 of development until birth. The first pineal anlage appears as a midline evagination of the diencephalic roof, which soon adopts a tubular morphology. At 17 days, the disappearance of the pineal recess begins, along with the transformation of the gland into a solid organ. The latter is mainly achieved by an infolding and thickening of the dorsal recess wall, from which derives most of the future pineal parenchyma. Blood vessels are mainly derived from the vessels found in the dorsal surface of the pineal gland.
A restudy of cardiac conduction pathways by techniques for visualization of cholinesterase reaction
Authors: Copenhaver Wilfred M. 
Published: February 2005

AbstractHistochemical reactions which demonstrate cholinesterase reactions in tissues were used for slides of serial frozen sections of hearts of pigs, dogs, and rats to determine whether there are special types of modified muscle cells in continuous pathways from the SA (sinoartial) to the AV (atrioventricular) node. There were positive reactions for acetylcholinesterase with less reaction for butyrl cholinesterase in ganglion cells and nerve fibers. No continuous pathways of cholinesterase‐reacting cardiac muscle fibers from the SA to the AV node were identified although the muscle fibers were in intimate relation with the nerve fibers. No cells of Purkinje type were demonstrated in the atria.
Evidence for the site of the superior salivatory nucleus in the guinea pig: A retrograde HRP study
Authors: Way John S. 
Published: February 2005

AbstractHorseradish peroxidase (HRP) was applied to the proximal end of the severed lingual nerve distal to where it was joined by the chorda tympani nerve in 15 female guinea pigs. Labeled cells were seen in the lateral reticular formation dorsal to the facial nucleus along the medial edge of the spinal nucleus of V. These cells were aligned vertically and partially within the facial nerve fibers which were emerging from the facial nucleus lying ventrally. HRP‐reactive axons were also seen among the facial nerve fibers coursing dorsomedially toward the genu of the facial nerve. These results demonstrated for the first time the locus of the superior salivatory nucleus in the guinea pig and were consistent with anatomical results previously reported in other species. In addition, labeled fibers indicated that superior salivatory nucleus axons became incorporated in the facial nerve immediately dorsal to its origin.
Topography of the deep cortex of the lymph nodes of various mammalian species
Authors: Bélisle C. , Sainte‐Marie G. 
Published: February 2005

AbstractIn preceeding studies, we clarified the histology of the deep cortex of the rat lymph node. It was shown that the deep cortex is made up of basic elements termed “deep cortex units,” some of which are fused to one another into “deep cortex complexes.” Each unit is a semirounded lymphocytic structure, centered on the opening of an afferent lymphatic, contiguous to the peripheral cortex, and bulging into the medulla of a node. Moreover, each unit comprises a “center” and a “periphery,” bearing distinct morphological features. The present work was undertaken to verify whether the histology of the deep cortex of nodes from various species of mammals, currently used for experimental immunology, is comparable to that of the rate. The observations yielded a positive answer to the question.
An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: I. Normal fibroblasts
Authors: Cho Moon‐Il , Garant Philias R. 
Published: February 2005

AbstractAnalysis of electon microscopic radioautographs revealed a maximum labeling with 3H‐proline of rough endoplasmic reticulum (RER) at 3 minutes, Golgi saccules 1 and 2 at 10 minutes. Golgi saccules type 3 at 20 minutes, and presecretory and secretory granules at 30 minutes. Labeling of the extra‐cellular collagen matrix occurred at 30 minutes and increased with time. These observations suggest that pro‐a‐chains of collagen in periodontal ligament fibroblasts are synthesized in the RER and transported to the Golgi apparatus within 10 minutes. These chains then undergo parallel alignment in Golgi saccules type 2 and form segment‐long‐spacing‐like crystallites in Golgi saccules type 3 between 10 and 20 minutes. The peak labeling of presecretory granules and mature secretory granules in small amounts at 30 minutes and the rapid increase in labeling of extracellular collagen matrix which begins at 30 minutes, indicates that the formation of secretory granules requires approximately 30 minutes and that a rapid system of secretory granule translocation exists in periodontal ligament fibroblasts. This evidence futher supports the previously published morphologic evidence for a microtubuledependent system of collagen secretion in periodontal ligament fibroblasts (Cho and Garant, 1981b).
The ultrastructure of isolated glial (Müller) cells from the turtle retina
Authors: Sarthy P. Vijay , Bunt Ann H. 
Published: February 2005

AbstractSarthy and Lam (1978) described a method for isolation of glial (Müller) cells from turtle retina which involves papain treatment, mechanical dissociation of the retinae, and subsequent separation of the dispersed cells by velocity sedimentation at unit gravity. In order to establish the cytologic integrity and the extent of contamination, we have carried out ultrastructural studies on the isolated cells using scanning and transmission electron microscopy. During the course of these studies we have also examined the effect of papain on the morphology of the retina. Scanning electron microscopic studies show that the isolated cells have a free surface with limited extraneous material attached. The basal portion of the cell is organized as end bulbs with a convoluted surface while the apical region is specialized with long microvilli. Transmission electron microscopy shows that the isolated cells have intact plasma membranes with very few interruptions. The cytoplasm is dense and contains the normal complement of smooth endoplasmic reticulum, microtubules, and filaments. The extent of contamination as estimated from serial sections of a single cell is about 10–15% of the total cell volume. These studies indicate that Müller cells isolated by this technique should be useful for metabolic studies and for characterizing the Müller cell surface.
Isolation, culture, and preliminary characterization of mucin‐producing cells from trachea of the domestic fowl
Authors: Douglas W. H. J. , Gustafson A. W. , Aghajanian J. D. , Gustafson E. Y. 
Published: February 2005

AbstractPrimary cell cultures enriched in mucin‐producing cells and basal cells were established from the trachea of the domestic fowl. Epithelial cells were selectively removed from the trachea after incubation in 0.1% pronase/0.1% EDTA in Moscona's saline. The majority of the ciliated cells were removed during the initial 30 minutes of incubation. After 50 minutes of incubation, aggregates of mucin‐producing cells and basal cells were removed in large numbers. The cellular aggregates rapidly attached to a collagen‐coated substratum and the cells spread out on the culture surface. The mucin‐producing cells retained their AB/PAS‐reactive secretory granules. The basal cells replicated and as the culture approached confluency, these cells developed a fine dusting of AB/PAS‐reactive material; later, larger secretory granules appeared in the cells. These observations suggest that mucin‐producing cells are capable of retaining their AB/PAS‐reactive secretory products in primary culture and that basal cells are capable of differentiating into mucin‐producing cells in vitro.
The morphology of canine lymphatic valves
Authors: Albertine Kurt H. , Fox Linda M. , O'Morchoe Charles C. C. 
Published: February 2005

AbstractThe architecture of 60 valves from thoracic ducts and from renal hilar and mesenteric collecting lymph vessels of dogs were studied by scanning electron microscopy as well as by light and transmission electron microscopy. All of the valves seen in hilar and mesenteric lymph vessels and most of those studied in the thoracic duct were bicuspid. An occasional tricuspid and one monocuspid valve was seen in the thoracic duct. The semilunar cusps of the valves extended from the vessel wall, to which they were attached, towards the valve outlet where adjacent cusps fused. Coincident to the area of fusion was the formation of mesenteric‐like folds or buttresses that anchored the cusps to the vessel wall. These folds extended 50–100 μm beyond the cusp margins on the outflow side of the valve. The attachments of the cusps, buttresses, and vessel wall to one another resulted in the formation of postvalvular sinuses, such that raised intraluminal pressure downstream to valve areas would distend the sinuses, causing leaflet apposition and hence valvular closure. The morphology of the valves was such that they were not considered to provide any significant impediment to the antegrade flow of lymph.
Comparison of lens regeneration in adult newts, Triturus viridescens, between light and dark preadapted and non‐preadapted animals
Authors: Chan Frank 
Published: February 2005

AbstractIt is well known that if the original lens is removed from the eyeball in certain Urodeles, a new lens will regenerate from the dorsal iris. Experiments were designed to study the different effects on lens regeneration in the newt, Triturus viridescens, between the light and dark preadapted animals and light and dark non‐preadapted animals. The preadapted animals were preadapted to continuous light or dark for 90 days prior to lentectomy. The newts remained in the same controlled environments postlentectomy for 25 days to test the effect of light preadaptation on lens regeneration. The non‐preadapted animals were placed in the light controlled environment immediately after lentectomy for a 25‐day regeneration period.The results indicated that there was no difference in the rate of regeneration between continuous light preadapted and non‐preadapted animals. However, the dark non‐preadapted animals regenerated new lenses at a much slower rate than the dark preadapted animals.The rate of lens regeneration was similar among the controls with 12 hours of light per 24‐hour period, the dark preadapted, the continuous light preadapted, and continuous light non‐preadapted groups.
Intraarterial cushions of the rat uterine artery: A scanning electron microscope evaluation utilizing vascular casts
Authors: Kardon Randy H. , Farley Donna B. , Heidger Paul M. , van Orden Dianna E. 
Published: February 2005

AbstractThe intraarterial cushions present in the rat at the points of branching of the main uterine artery have been studied by means of scanning electron microscopy. Such studies confirmed the three‐dimensional concept of these structures gained from previous light microscopic serial section reconstructions as incomplete, raised, asymmetric ridges which encompass the branch orifice. The examination of methacrylate corrosion casts of the uterine vasculature with the scanning electron microscope provided a means for evaluating the relative protrusion or retraction of the cushion structures within the vessel lumen, and thus for assessing their role in regulating uterine blood flow in various physiologic states. Cushions were studied in this manner at the stages of the estrous cycle, in castrated animals, and in animals receiving pharmacologic doses of an alpha adrenergic agonist, phenylephrine. Evaluation of the relative depth of the impression left upon the vascular casts by cushions permitted the following conclusions. The cushions protruded maximally (and thus impeded flow most effectively) in castrated animals and in animals treated with the vasoconstrictor, phenylephrine. In contrast, the cushions protruded less in animals in proestrus and estrus. These data suggest that the cushions do respond, either actively, by virtue of the contractile state of the smooth muscle within the cushion, or passively, as a function of overall vessel geometry, to alpha adrenergic stimulation. The contrast in cushion protrusion between the castrated state, and proestrus and estrus, suggests that ovarian hormones exert an influence over the functional morphology of the cushions in a manner which promotes maximal uterine perfusion during those periods of the estrous cycle which are documented as periods of uterine hyperemia. These studies thus provide evidence for the dynamic role of intraarterial cushions in the regulation of uterine blood flow.
Correlates of ovarian morphology, estrous behavior, and cyclicity in an inbred strain of miniature swine
Authors: Howard Paul K. , Chakraborty Prabir K. , Camp Jonathan C. , Stuart Leonard D. , Wildt David E. 
Published: February 2005

AbstractOvarian morphology and behavioral relationships were studied in a group of nine miniature pigs with a characteristically small litter size (∼5) and an average coefficient of inbreeding of 0.39. The first day of standing estrus was designated as day 0. Laparoscopy was used to evaluate and photograph ovarian activity on days 1, 5, 11, 17, and day 2 of the subsequent estrous cycle. Mean (±SEM) duration of estrus and the estrous cycle was 3.1±0.2 and 22.6±0.3 days, respectively. An average of 9.0±0.4 vesicular follicles developed/estrous period and 96% of the follicles showed morphologic evidence of ovulation resulting in a mean of 8.6±0.3 corpora lutea (CL) per animal. There was no significant correlation between the degree of inbreeding and number of vesicular follicles (r=0.27) or CL (r=0.28) developing/cycle within the experimental group. Mature preovulatory follicle and CL size ranged from 6–12 mm and 8–12 mm in diameter, respectively, and 22.5% of the newly formed CL contained distinct postovulatory stigmata. These data indicated that 1) temporal relationships of sexual behavior and gross ovarian morphology in the miniature pig were similar to descriptions previously reported for the standard pig, and 2) the reduced litter size characteristic to this particular strain is, at least in part, due to decreased number of vesicular follicles developing during the estrous cycle.
Plexus muscularis profundus and associated interstitial cells. II. Ultrastructural studies of mouse small intestine
Authors: Rumessen Jüri Johannes , Thuneberg Lars , Mikkelsen Hanne Birte 
Published: February 2005

AbstractThe ultrastructure of plexus muscularis profundus (PMP) of the mouse small intestine was investigated subsequent to vascular perfusion with ruthenium red‐containing and routine aldehyde fixatives. Four types of nerve terminals were revealed. Type I: numerous 500‐Å agranular vesicles and few 1,000‐Å granular vesicles. Type II: predominantly large (1,000–1,500 Å), granular vesicles and fewer 500‐Å agranular vesicles. Type III: an abundance of mitochondria and many flattened vesicles (300 Å × 700‐1,300 Å). Type IV was identified by abundant smooth cisternae 200 Å in width. Types I‐III formed close (200 Å), synapselike contacts to interstitial cells of Cajal (ICC‐III). Presynaptic densities were frequent in type I endings. A direct innervation of muscle cells via PMP was only very occasionally suggested. ICC‐III possessed a basal lamina and numerous caveolae associated with subsurface SER‐cisternae. Mitochondria were very abundant in ICC‐III‐processes. ICC‐III formed multiple, large gap junctions with outer circular‐muscle cells and with other ICC‐III. Also reflexive gap junctions were observed. Fibroblastlike cells (FLC) were distinguished by their prominent GER, the frequent presence of lipid droplets, and the lack of caveolae and a basal lamina. FLC never participated in synaptic arrangements or gap junctions. Macrophagelike cells were occasionally encountered. It is concluded that possible efferent and afferent nerve terminals in PMP may chiefly, if not exclusively, innervate ICC‐III, the ultrastructure of which is compatible with efferent and/or afferent modulatory actions.
Degranulation of endothelial specific granules of the toad aorta after treatment with compound 48/80
Authors: Fujimoto Sunao 
Published: February 2005

AbstractIncubation of isolated toad aortas in Ringer solution containing compound 48/80, a Histamine liberator, resulted in marked degranulation of endothelial specific granules.Since incubation of these vessels in Ringer solution only did not show significant morphologic changes in these granules, these findings suggest that the degranulation was induced by histamine release from the granules, as in the case for mast cell degranulation, and that endothelial specific granules are a storage site of histamine in the toad aorta.The present morphologic data were supported by preliminary chromatography, which showed appreciable concentrations of histamine in the granule‐containing pellets of subcellular fractions of homogenized toad aortas.
A comparative study of osteoclasts: In situ versus smear specimens Osteoclasts in situ and in smears
Authors: Ries William L. , Gong Joseph K. 
Published: February 2005

AbstractOsteoclasts residing on rims and walls of bony concavities on remodeling proximal Libia from growing rats were examined by light microscopy following stripping of the periosteal connective tissue layer. Comparison of these cells in situ and after transfer to glass slides revealed the presence of numerous mononucleate osteoclasts, as well as typical multinucleate forms, all exhibiting a ruffled border and acid phosphatase and succinic dehydrogenase activity. Macrophage‐like cells were situated adjacent to osteoclasts in situ. Osteoblasts were relatively inconspicuous. The possibility that the basic functional osteoclast unit is a mononucleate cell is discussed.
Distribution of progesterone in the uterus, broad ligament, and uterine arteries of beef cows
Authors: Pope W. F. , Maurer R. R. , Stormshak F. 
Published: February 2005

AbstractSamples of uterine horn, broad ligament (mesosalpinx and mesometrium), and uterine artery of ten unilaterally ovulating cows, 12–15 days after mating, were examined for differences in concentration of progesterone. Tissues (mesosalpinx, branches of the uterine artery, anterior uterine horn) adjacent to the ovary bearing the corpus luteum contained significantly greater quantities of progesterone than more distal tissues (mesometrium, uterine artery, posterior uterine horn) on the same side and all tissues on the contralateral side. In tissues on the side ipsilateral to the corpus luteum, a gradient of progesterone existed. Differences in tissue concentrations of progesterone may be the cause of observed differences in uterine physiology in the cow and ewe.
An ultrastructural morphometric comparison of the right and left sides and lobes of the dog lung
Authors: Berendsen Peter B. , De Fouw David O. 
Published: February 2005

AbstractRegional variations of the components of lobes of the lung have been recognized to result from gravitational effects. Excised and isolated perfused lungs are frequently used as objects for studies of fluid flow. This ultrastructural study considered differences between the right and left sides and lobes of the excised lung. The lungs of three mongrel dogs were fixed by simultaneous endotracheal instillation of glutaraldehyde and immersion in fixative. Stratified random sampling, point‐counting volumetry, and line intercept counts were utilized to determine the volume densities of alveolar space, endothelial vesicles, interstitial cells, fibers, and matrix. Thicknesses of the air‐blood barrier, epithelial, interstitial, and endothelial compartments were measured. Values for the right side were compared to values for the left by t‐test. Values for lobes were compared statistically by a two‐way analysis of variance. There was no statistically significant column effect, no row effect, and no interaction between the mean measurements of the factors computed for the right and left lungs and the lobes within the lungs. It is concluded that stratified random sampling combined with endotracheal and immersion fixation as used in this study equalize regional differences in the alveolar lumen volume and air‐blood barrier thickness. With these conditions there are no significant differences by sides or lobes in the volume densities of the epithelial and endothelial cells and components of the interstitium of the air‐blood barrier.
Secondary myogenesis of normal muscle produces abnormal myotubes
Authors: Ontell Marcia , Hughes Donna , Bourke Dianna 
Published: February 2005

AbstractThe extensor digitorum longus muscles of 2‐, 4‐, and 12‐week‐old 129‐ReJ mice were subjected to homotopic, whole‐muscle transplantation. Subsequent to myofiber necrosis and phagocytosis, a new population of myotubes was produced. The three‐dimensional cytoarchitecture of these newly formed myotubes was determined in spaced, serial, ultrathin sections. Myotubes, which for long distances along their length appeared to be separate and discrete, were found to branch and recombine, forming a complex syncytium.
Inhibition of artificially induced decidual cell reaction by indomethacin in the mature oophorectomized rat
Authors: Miller Marilyn M. , O'Morchoe Charles C. C. 
Published: February 2005

AbstractProstaglandin F2α (PGF2α) is capable of inducing a decidual cell reaction (DCR) in the hormonally prepared rat. In the present work indomethacin, a PG synthetase inhibitor, was used to determine whether PGF2α is involved in the DCR induced by artificial stimulation of the endometrium. Thirty‐seven animals were oophorectomized and subsequently given daily injections of progesterone for 6 days and one injection of estradiol 17 β on the fourth day. Later on the fourth day, one of several experimental maneuvers was carried out on the right uterine horn of each animal; these included: 1) introduction of phosphatebuffered saline (PBS) twice into the uterus, 2) intrauterine injection of PGF2α with no subsequent application or manipulation, 3) intrauterine injection of indomethacin followed by subsequent injection of PGF2α, 4) intrauterine injection of indomethacin with subsequent artificial stimulation (scratch), 5) intrauterine injection of PBS with subsequent scratch, 6) scratch followed by injection of PBS, and 7) scratch followed by a second scratch. The extent of the ensuing DCR was assessed 48 h later by measurement of horn weight, by light and electron microscopy, by ranking the DCR, and by the mitotic index. Indomethacin significantly reduced the horn weight in animals treated with scratch but had a much less marked effect on animals treated with PGF2α. Similarly the rank of the DCR and the mitotic index were significantly less in endometria treated by indomethacin with scratch than those treated by indomethacin with PGF2α. From these findings it was concluded that the DCR induced by scratch was inhibited, but not abolished, when preceded by indomethacin. Conversely the DCR induced by PGF2α was not inhibited by indomethacin, thus demonstrating that when local generation of PG is reduced or abolished, PGF2α can sustain the decidual cell response.