bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adipocyte development in primary rat cell cultures: A scanning electron microscopy study
Authors: Richardson R. L. , Hausman G. J. , Campion D. R. , Thomas G. B. 
Published: February 2005

AbstractThis study utilized scanning electron microscopy (SEM) techniques to observe primary cultures of stromal‐vascular (SV) cells derived from postnatal rat inguinal adipose tissue. Cells were grown on collagen‐coated, fibronectin‐coated, or uncoated glass coverslips. Coverslips were normally fixed in glutaraldehyde, osmium tetroxide, dehydrated, and critical‐point‐dried. Other coverslips were frozen in isopentane (cooled in LN2) and dried or fixed in Baker's formalin for demonstration of inosine diphosphatase (IDPase) by X‐ray microprobe analysis (XRMA). Adipocyte morphologies were similar on all substrates. At 2 days of culture, actin cables were detected extending from developing adipocytes. No difference in actin cable structure, cellular shape, or lipid accumulation was observed among the different substrates. Some stromal cells did not accumulate lipid but proliferated into a multilayer by 9 days in culture. Inosine diphosphatase was detected in the Golgi apparatus of developing adipocytes utilizing the technique of XRMA. This study demonstrates the potential for using SEM and XRMA techniques to define morphological features and cytochemical markers of adipocytes in vitro and the response of primary cultured rat SV cells to other attachment substrates.
Prenatal development of the composite occipito‐atlanto‐axial synovial joint cavity in the dog
Authors: Watson Alastair G. , De Lahunta Alexander , Evans Howard E. 
Published: February 2005

AbstractIn the dog, the synovial cavities of the atlanto‐occipital and atlanto‐axial joints communicated to form a single large composite joint cavity. The prenatal development of this composite occipito‐atlanto‐axial joint cavity was studied by examining 26 serially sectioned dog embryos and fetuses that ranged in size from 19 to 68 mm crown‐rump length, and were between 30 and 42 days of gestational age. In the composite occipito‐atlanto‐axial joint, trilaminar interzones developed at 19–22 mm (30–31 days), joint cavities opened at 27–32 mm (33–34 days), and the atlanto‐occipital and atlanto‐axial cavities first communicated at 48 mm (37 days).
A rare human variation: The relationship of the axillary and inferior subscapular nerves to an acessory subscapularis muscle
Authors: Breisch Eric A. 
Published: February 2005

AbstractA case of bilateral occurrence of a variant subscapularis muscle is reported. The superior lateral aspect of each subscapularis muscle presented a small accessory muscle with an accompanying tendon that inserted into the lesser tubercle of the humerus along with the primary tendon of the subscapularis muscle. Each accessory subscapularis muscle was separated from the primary subscapularis muscle by the axillary and inferior subscapular nerves. No branches of the axillary or inferior subscapular nerves supplied the primary subscapularis muscle or the accessory muscle while the nerves passed through the myotendinous tunnel. The relationship of the nerves with the variant subscapularis muscles has clinical significance with regard to entrapment neuropathy.
Nomenclatural review of long digital forelimb flexors in carnivores
Authors: Spoor C. F. , Badoux D. M. 
Published: February 2005

AbstractA hitherto‐unknown atavistic muscle in the dog initiated a review of the literature on the homologies and nomenclature of the forelimb flexors in carnivores and man. A consequence is that we recommend a revision of the nomenclature in the Nomina Anatomica Veterinaria (Ithaca, New York, 1983) so that it is in agreement with the Nomina Anatomica (Wilkins, Baltimore, 1983). This revision mainly consists of the incorporation of the terms M. palmaris longus and Mm. flexores breves manus.
Spatial distribution of twitch and tonic fibres in a snake muscle one myofibre thick
Authors: Robinson Andrew J. 
Published: February 2005

AbstractThe spatial distribution of twitch and tonic fibres in a snake muscle one myofibre thick (ventral costocutaneous) has been investigated. It was found that small groups of like fibres were favoured at the expense of larger groups when compared with sequences generated by a computer in which fibres were distributed randomly. The number of times that like fibres occurred next to one another was used as another measure of their spatial distribution. The number of adjacencies of like fibres was less than the expected number of adjacencies determined both by random sequences and by probability theory. The expected number of adjacencies determined by means of random sequences and a priori probability theory were almost identical. This dispersion of like fibres may reflect processes that occur during muscle development and may have functional implications.
Endocytic appartus and transcytosis in epithelial cells of the vas deferens in the rat
Authors: Hermo L. , de Melo V. 
Published: February 2005

AbstractThe apex of the principal epithelial cells lining the vas deferens of the rat contains coated pits in continuity with the apical plasma membrane and large subsurface‐coated vesicles (100–125 um). In the apical cytoplasm, large, pale, uncoated vesicles (150–300 nm), small coated and uncoated vesicles (50–60 nm), uncoated vesicles about 75–90 nm, and membranous apical tubules are present, in addition to large, vacuolar, pale, multivesicular bodies, dense multivesicular bodies, and secondary lysosomes seen deeper in the cytoplasm amongst numerous ER cisternae, saccules of the Golgi apparatus, and mitochondria.The endocytic activity of these cells was investigated by using cationic ferritin (CF) as a marker of adsorptive endocytosis and native ferritin (NF) for demonstrating fluid‐phase endocytosis. These tracers were injected separately into the lumen of the vas deferens, and the animals were killed at various time intervals thereafter from 2 to 90 minutes. At 2 minutes CF was seen bound predominantly to microvilli and to areas of the apical plasma membrane delimiting coated pits as well as in large, coated vesicles. At 5 and 15 minutes the tracers were seen in apical tubules and pale multivesicular bodies; at 30 minutes moderately dense multivesicular bodies were labeled. At 1 hour and longer time intervals dense multivesicular bodies and secondary lysosomes were labeled. NF followed the same pathway as CF; however, no binding to microvilli or areas delimiting coated pits was observed. The numerous other vesicular structures, i.e., the large uncoated vesicles (150–300 nm) and the small coated and uncoated vesicles (50–60 nm), never became labeled with the tracers and therefore were not involved in the endocytic process. There was, however, and exception in the case of several small (75–90 nm) uncoated vesicles seen deeper in the apical cytoplasm of these cells which were labeled exclusively with CF. With time such vesicles appeared along the lateral and basal surfaces of these cells and discharged their content of CF into the lateral intercellular space or the connective tissue space at the base of these cells. Thus the principal epithelial cells in addition to sequestering the endocytosed tracers within secondary lysosomes where they are presumably degraded also appear to be involved in the transcytosis of material from the lumen of the vas deferens to the underlying lamina propria.
Morphology of the osteonal cement line in human bone
Authors: Schaffler Mitchell B. , Burr David B. , Frederickson Richard G. 
Published: February 2005

AbstractWhile current consensus suggests the absence of collagen in osteonal cement lines, the extent of cement line mineralization and the nature of the ground substance within the cement line are unclear. Samples of human radius were examined by using scanning electron microscopy, electron microprobe, and histochemical techniques. X‐ray intensities were used to compare the amount of calcium, phosphorus, and sulfur in cement lines with amounts in surrounding lamellar bone. The results indicate that cement lines contain significantly less calcium and phosphorus, but significantly more sulfur, than surrounding bone matrix. The Ca/P ratio of cement lines was significantly greater than that of lamellar bone, suggesting that the mineral in cement lines may not be in the form of mature hydroxyapatite. No selective staining of the cement lines could be demonstrated by using periodic acid‐Schiff, Sudan black B, or alcian blue critical electrolyte concentration techniques.
Morphogenetic clonal growth of kidney epithelial cell line MDCK
Authors: McAteer James A. , Evan Andrew P. , Gardner Kenneth D. 
Published: February 2005

AbstractMDCK (Madin‐Darby canine kidney) cells were cultured either (1) dispersed within hydrated collagen gel (HCG) or (2) seeded atop a collagen substrate and then immediately overlaid with HCG. Individual cells exhibited clonal growth in three dimensions to form spherical cysts made up of a simple epithelium enclosing a fluid‐filled lumen. The cells of MDCK cysts were polarized with the basolateral surface in contact with the collagen gel and the apical surface bordering the lumen. The ultrastructure of MDCK cysts showed similarities to distal nephron. The cells bore apical microvilli and solitary cilia and had occluding junctions and a simple basolateral surface. MDCK cysts increased in size (> 800 μm diameter) with continued culture. MDCK cysts grown between layers of HCG were stripped free of the overlying collagen to give direct access to basolateral surface membrane. Unlike monolayer culture, morphogenetic clonal growth of cell line MDCK produces a polarized cell population with a true lumenal and basolateral surface. Collagen‐gel‐cultured MDCK cysts provide an easily manipulable in vitro cell system that may offer unique advantages for the study of renal cell structure and function.
Localization of calcium in vas deferens using 45Ca EM autoradiography: Relationship to species and the effect of 45Ca removal
Authors: McGuffee Linda J. , Little Sally A. , Skipper Betty J. 
Published: February 2005

AbstractThe distribution of calcium was determined in the vas deferens of the guinea pig using 45Ca electron microscopic autoradiography of rapidly frozen, freeze‐dried, and embedded tissue. A selective accumulation of calcium at the plasma membrane and SR was observed in vas deferens that had been incubated in 45Ca for 65–85 min prior to rapid freezing. Rinsing the tissue in nonradioactive calcium for 6 min prior to rapid freezing significantly altered the distribution of calcium among the plasma membrane, mitochondria, and cytoplasmic matrix. The influence of species on the observed distribution of calcium was also examined. The distribution of calcium in the guinea pig was deferens was not significantly different from that in the rabbit vas deferens when the tissues were prepared under identical conditions.
A classification of Sharpey's fibers within the alveolar bone of the mouse: A high‐voltage electron microscope study
Authors: Johnson Roger B. 
Published: February 2005

AbstractIn the remodeling interdental septum of the mouse, four types of Sharpey's fibers were observed. Classification of these fiber types was based on characteristics of their termination within the septum in relation to the resorption‐related reversal line separating old and new bone. “Severed fibers” were located only within old bone and terminated at the reversal line. “Arborized fibers” were located only within new bone and terminated therein. “Adhesive fibers” were located within new bone and terminated within a heavy band of granular material at the reversal line. “Continuous fibers” had components within old and new bone. These components were connected across the reversal line by nonstriated fibrils. Adhesive fibers were the least numerous type; severed and arborized fibers were observed at nearly equal frequency. Continuous fibers were the most numerous type, their numbers being significantly greater than any of the other types (P<.001). Mean numbers of continuous fibers were greater than the mean total of the three other fiber types (P<.001). Mean numbers of severed, adhesive, and arborized fibers were not statistically different. The study suggested that continuous fibers could be transalveolar—that is, ones which pass through the septum without interruption joining fibers of the adjacent periodontal ligament. Maintenance of their spatial continuity appeared to require a connecting protein to orient new unit collagen fibrils to old ones in areas of reversal. Thus, transalveolar fiber bundles could be characterized as being composed of old and new segments joined by a connecting protein. As their unit collagen fibrils did not cross resorption‐related reversal lines these fibers were spatially continuous but temporally discontinuous.
Specific binding sites for transferrin on ameloblasts of the enamel maturation zone in the rat incisor
Authors: McKee M. D. , Zerounian C. , Martineau‐Doizé B. , Warshawsky H. 
Published: February 2005

AbstractDuring enamel maturation in rodents, an iron‐containing pigment is deposited into the surface layer of the enamel. Maturation zone ameloblasts presumably are responsible for this deposition. The presence of large amounts of ferritin in the cytoplasm of these cells suggests that they receive iron, presumably from circulating transferrin. An in vivo radioautographic binding assay using iodinated transferrin was used to determine if indeed maturation ameloblasts possess transferrin receptors at their cell surfaces. Experimental rats received systemic injections of labeled transferrin while control rats received injections of labeled transferrin plus a large excess of unlabeled transferrin in order to complete with the labeled transferrin for available specific receptors. Light microscope radioautography showed that ruffle‐ended ameloblasts (RAs) of the enamel maturation zone had a high density of specific receptors for transferrin relative to smooth‐ended ameloblasts (SAs). Electron microscopy and energy‐dispersive X‐ray spectroscopy confirmed the presence of ferritin and iron, respectively, within these cells. It is postulated that the iron responsible for enamel pigmentation is transported by transferrin to maturation ameloblasts and is bound to specific transferrin receptors found mostly on RAs and that the modulation of these cells into SAs results in a loss of most of these receptors.
Differential uptake of 3H‐thymidine by structures of the pia‐arachnoid and cerebral cortex distal to the interrupted middle cerebral artery
Authors: Myers Steven F. , Coyle Peter 
Published: February 2005

AbstractTritiated thymidine accumulated in pial surface structures 1–10 days after interruption of the right middle cerebral artery (MCA) in the rat. Essentially no radioactive marker was present in the underlying cortical territory of the interrupted MCA other than at the operation site. Control meninges, cortex contralateral to the operated MCA, and structures proximal to the operation site were without appreciable accumulation of 3H‐thymidine. Thus, the marked cellular proliferative response to MCA interruption was localized to structures of the pia‐arachnoid overlying the cortical territory of the interrupted MCA. The data suggest that after MCA occlusion a cellular proliferative response contributes to the expansion of preexisting pial surface collateral vessels and that the expansion does not extend into the parenchyma.
Cell cycle and neuroepithelial cell shape during bending of the chick neural plate
Authors: Smith Jodi L. , Schoenwolf Gary C. 
Published: February 2005

AbstractNeuroepithelial cells change shape from spindle‐like to wedge‐like within three restricted areas (hinge points) of the bending neural plate. The mechanisms underlying these localized cell shape changes and the specific role that these changes play in bending are nuclear. This study was designed to determine whether changes in neuroepithelial cell shape involve basal cellular expansion owing to alteration of the cell cycle. Neurulating chick embryos were treated with colchicine to arrest and accumulate cells in metaphase, and colchicine indices and cell generation times were calculated for the neural plate. During bending of the neural plate, cell generation time in the median hinge point, which contains predominantly wedge‐shaped cells, was significantly longer than that in adjacent lateral areas of the neural plate, which contain predominantly spindle‐shaped cells. In addition, cell generation time in the flat neural plate, which contains predominantly spindle‐shaped cells and has not yet differentiated into the median hinge point and lateral subdivisions, was identical to that in lateral areas of the bending neural plate but was significantly shorter than that in the median hinge point. These results support the hypothesis that changes in neuroepithelial cell shape from spindle‐like to wedge‐like involve basal cellular expansion owing to alteration of the cell cycle. Additional tests of this hypothesis and studies on the role of localized cell shape changes in neurulation are in progress.
Morphologic characterization of cultured smooth muscle cells isolated from the tracheas of adult dogs
Authors: Tom‐Moy May , Madison J. Mark , Jones Cary A. , de Lanerolle Primal , Brown James K. 
Published: February 2005

AbstractThe goals of our study were to isolate smooth muscle cells from the trachealis muscle of adult dogs and to characterize the cells morphologically when they were maintained in primary culture. Enzymatic digestion of the muscle yielded 4.8 ± 1.8 × 106 viable smooth muscle cells per gram of tissue. When placed in culture, these cells rapidly proliferated until confluence was reached. The proliferating cells in culture differed from the cells in the intact tissue in that they stained less intensely for smooth muscle myosin, developed immunoflurescent staining for the intermediate filament protein vimentin, and lost many of the ultrastructural properties of the intact muscle. Only within nodules of cells in the confluent cultures were these ultrastructural properties preserved. Cultures of canine tracheal fibroblasts differed from these smooth muscle cell culturs in that the fibroblasts did not stain for smooth muscle myosin and did not form nodules at confluence. We concluded that adult canine airway smooth muscle cells may be maintained in primary culture, that the confluent cultures contain nodules of cells with many morphologic characteristics of the intact muscle, and that these preparations may be distinguished from cultured canine tracheal fibroblasts on specific morphologic grounds.
Heterotopic synaptic bodies in the auditory hair cells of adult lizards
Authors: Miller Malcolm R. , Beck Janet 
Published: February 2005

AbstractThe auditory hair cells of adults of eight species of lizards (three gekkonids: Coleonyx variegatus, Gekko gecko, and Cosymbotus platyurus; two teiids: Ameiva ameiva and Cnemidophorus tigris; one anguid: Celestus costatus; one lacertid: Podarcis (Lacerta) sicula; and one iguanid: Crotaphytus wislizeni) were studied by transmission electron microscopy. Heterotopic synaptic bodies were found in some of the auditory hair cells of all of the above species, occurring frequently in the gekkonids but infrequently in other species.The groups of heterotopic synaptic bodies occurred mainly in the infranuclear cytoplasm between the hair cell nucleus and the hair cell plasma membrane. The groups of synaptic bodies that were close to the hair cell nucleus were usually associated with specialized arrays of rough and smooth endoplasmic reticulum. The numbers of heterotopic synaptic bodies were greatest in the gekkonid species and were especially large in Coleonyx variegatus, where an average of 36.8 synaptic bodies occur in one group. The functional significance of the presence of heterotopic synaptic bodies in the auditory hair cells of adults animals is not known.
The “in situ” immune response in lymph nodes: A review
Authors: van Rooijen N. 
Published: February 2005

AbstractFor many years data on the development of specific antibody‐forming cells in lymph nodes were incomplete, fragmentary, and even contradictory. A number of recent studies have been performed, concerning (1) their overall architecture; (2) migration of B‐lymphocytes; (3) localization of accessory cells and T‐lymphocytes which are believed to be involved in humoral immune responses; and (4) localization patterns of specific antibody‐forming cells developing during thymus dependent and thymus independent immune responses. Comparison of these new results with those of earlier studies suggests a single route of migration followed by all cells which will differentiate into antibody‐forming cells. During their differentiation into antibody‐forming plasma cells, antigen reactive B‐cells migrate along the required accessory cells and/or T‐lymphocytes.
Regeneration of submandibular gland autografts in sympathectomized rats
Authors: O'Dell Norris L. , Sharawy Mohamed , Richardson Mary C. , Pennington Catherine B. 
Published: February 2005

AbstractThis morphologic study compares the regenerative response in submandibular gland (SMG) autografts placed in the tongues of previously sympathectomized rats to autografts placed in tongues of sham‐sympathectomized rats. We hypothesized that sympathectomy would alter the process of cellular proliferation and inhibit cytodifferentiation in regenerating SMG autografts. Either 1 week, or 8 to 11 weeks following the SMG autografting procedure, the rats were sacrificed and their tongues were removed and sectioned in a cryostat. Frozen tissue sections containing the SMG autografts were either reacted for cholinesterase activity, treated with a glyoxylic acid mixture to induce histofluorescence, or stained for histologic examination. In addition, 3H‐thymidine labeled and unlabeled cells were counted in autoradiographs of 1‐week autografts, and these counts were used to calculate labeling indices. The 1‐week SMG autografts from both the sympathectomized and the sham‐sympathectomized rats were similar in histologic appearance, and neither group of autografts contained cholinesterase‐positive or monoaminergic nerve fibers. The 8‐ to 11‐week autografts from sympathectomized and sham‐sympathectomized rats contained cholinesterase‐positive fibers, but monoaminergic fibers were present in the autografts only from the sham‐operated rats. Acinar cells were observed in one‐third of the 8‐ to 11‐week autografts of both the sympathectomized and the shamsympathectomized rats. This finding suggests that sympathectomy did not preclude cytodifferentiation in the autografts. The autoradiographic data revealed no statistically significant difference between the mean labeling indices of the 1‐week autografts from the sympathectomized and sham‐sympathectomized rats, which suggests that sympathectomy also did not alter the level of cellular proliferation in the autografts.