bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural observation of the trans‐Golgi associated plate‐like cisterna in the secretory cells of the rat anterior pituitary gland with special reference to the intracisternal skeleton
Authors: Inoue Kinji , Kurosumi Kazumasa 
Published: February 2005

AbstractA well‐developed plate‐like cisterna (PLC) associated with trans‐Golgi elements was observed in the Golgi apparatus of secretory cells in the rat anterior pituitary gland. This structure corresponds to the trans‐most sacculotubular network. The PLC maintains a remarkably uniform thickness of about 33 nm, as measured between the outer leaflets of its unit membrane structure. As to the mechanism by which this peculiar construction of the PLC is maintained, pillar‐like structures were noted in the PLC intracisternal space, apparently acting as supports to keep the intermembrane distance constant. The PLC was especially well developed in hypertrophied cells such as gonadotrophs following castration. One noteworthy feature was that the PLC frequently ran parallel with the rough endoplasmic reticulum (RER), maintaining a constant distance from the latter in hypertrophied cells, but no membrane continuity between the PLC and RER was seen.
Differential distribution and ultrastructural staining of oxytalan and elastic fibers in the periodontal ligament of Alligator mississippiensis
Authors: Takagi Minoru , Kazama Toshitada , Shimada Kazuyuki , Hosokawa Yasunobu , Hishikawa Hideki 
Published: February 2005

AbstractWe have investigated ultrastructural cytochemical properties of elastic elements in Alligator periodontal ligaments decalcified with EDTA and stained with 1) the tannic acid‐uranyl acetate (TA‐UA) method for elastin in combination with elastase digestion; 2) the high iron diamine‐thiocarbohydrazide‐silver proteinate (HID‐TCH‐SP) method with prior treatment of specimens with either monopersulphate or cupric‐sulphite reagent for the localization of disulphide‐ and/or sulphydryl‐containing material (i.e., oxytalan fibers); and 3) HID‐TCH‐SP alone for sulphated complex carbohydrates. Many microfibrils accumulated to form either large or small bundles. Large bundles having a diameter of 2.50 ± 1.10 μm (mean ± SD; n = 50) each showed an apico‐occlusal distribution, although small bundles measuring 0.63 ± 0.13 μm (mean ± SD; n = 50) in diameter each were exclusively localized in interstitial areas rich in vessels and nerves. The former bundles always lacked TA‐UA reactivity and represented oxytalan fibers; the latter bundles frequently contained TA‐UA‐reactive elastase digestable components and were similar in appearance to immature elastic fibers or elaunin fibers. HID‐TCH‐SP after oxidation strongly stained both the oxytalan and elastic fiber microfibrils but stained the amorphous elastin very weakly or not all. In nonoxidized specimens, there was no definite HID‐TCH‐SP staining of microfibrils and the amorphous elastin, although adjacent matrix proteoglycans stained consistently. These results indicate that although there is a marked difference in the distribution and size of oxytalan and elastic fibers in Alligator periodontal ligaments, their associated microfibrils lack stainable sulphate groups but are enriched with disulphide and/or sulphydryl groups, as has been described in mammals.
Effects of estradiol and progesterone on diabetes‐associated utero‐ovarian atrophy in C57BL/KsJ (db/db) mutant mice
Authors: Garris David R. 
Published: February 2005

AbstractThe modulating effects of estradiol (E: 1 μg/3.5 days) and progesterone (P: 2 mg/3.5 days) on the obesity and hyperinsulinemic and hyperglycemic components of the diabetes‐obesity syndrome in female C57BL/KsJ (db/db) mice, which includes cellular atrophy and adiposity in the reproductive tract, were examined and compared to corresponding control (+?) parameters. All control and diabetic mice received oil (vehicle control), E, or P treatments starting at 4 weeks of age. Body weight, serum insulin levels, blood glucose concentrations, and uteroovarian lipoprotein lipase activites were analyzed at 8 and 16 weeks of age and related to the ultrastructural changes in the steriod‐sensitive uterine epithelium during the treatment period. Neither E nor P had any effect on body weights in (+?) or (db/db) mice. The pronounced diabetes‐associated elevation in serum insulin levels was enhanced by E, and suppressed by P, in 16‐week‐old (db/db) mice as compared with controls. By 16 weeks of age, the E therapy normalized blood glucose levels in diabetic mice to control levels, whereas P was ineffective in modulating the hyperglycemia. The reduction in blood glucose levels in E‐treated diabetic mice correlated temporally with the return of normal intracellular structure including the disappearance of intracellular lipid vacuoles characteristic of uterine epithelium cells of (db/db) mice. The diabetes‐induced rise in utero‐ovarian lipoprotein lipase activity was normalized by P‐therapy. The reduction in uteroovarian lipoprotein lipase activity coincided temporally with the demonstrated intracellular reorganization in (db/db) reproductive tract tissues. These data indicate that E and P therapies are effective modulators of mutation‐induced structural, metabolic, and functional changes in the reproductive tract and peripheral tissues of genetically diabetic C57BL/KsJ (db/db) mice. The ability to restore affected tissue structure and function in this mutant mouse model to that of controls suggests that gonadal steroids may correct, delay, prevent, or suppress the diabetes‐associated tissue atrophy and adiposity which characterizes this strain.
Binding of the blood group‐reactive lectins to human adult kidney specimens
Authors: Laitinen Liisa , Juusela Harri , Virtanen Ismo 
Published: February 2005

AbstractThe binding of a panel of blood group‐reactive lectins to frozen sections of human kidney was studied with a special emphasis on reactivity with endothelia and basement membranes. The blood group A‐reactive lectins, all specific for α‐D‐N‐acetylgalactosamine (GalNAc), Helix aspersa (HAA), Helix pomatia (HPA), and Griffonia simplicifolia I‐A4 (GSA‐I‐A4) agglutinins bound to the endothelium in specimens with blood groups A and AB. In other samples, these lectins reacted predominantly with tubular basement membranes, as well as with certain tubules. Both Dolichos biflorus (DBA) and Vicia villosa agglutinins (VVA), reported to react with blood group A1 substance, failed to reveal endothelia in most specimens, but bound differently to tubules in all blood groups. The blood group B‐reactive lectins, specific for α‐D‐galactose (α‐Gal) or GalNAc, respectively, GSA‐I‐B4 and Sophora japonica agglutinin (SJA), bound to the endothelia in specimens from blood group B or AB and in other specimens bound only to certain tubules. Among the blood group O‐reactive lectins, specific for α‐L‐fucose (Fuc), Ulex europaeus I agglutinin (UEA‐I) conjugates, but not other lectins with a similar nominal specificity, bound strongly to endothelia in specimens with blood group O. The UEA‐I conjugates bound distinctly more faintly to endothelia in specimens of other blood groups. The present results indicate that lectins, binding to defined blood group determinants, react with endothelia in specimens of the respective blood group status. Furthermore, they suggest that basement membranes and some tubules in the human kidney show a distinct heterogeneity in their expression of saccharide residues, related to their blood group status.
Structural characteristics of staircase‐type retzius lines in human dental enamel analyzed by scanning electron microscopy
Authors: Risnes S. 
Published: February 2005

AbstractBased on a scanning electron microscopic (SEM) analysis of adjoining, acid‐etched planes cut through human cervical enamel, the structural characteristics of staircase‐type Retzius lines have been clarified. Structural features associated with this type of Retzius lines–such as cleftlike defects, decreased dimension of prisms, increased interprism, club‐shaped appearance of prisms, oblique ridges, and triangular regions–have been incorporated into a unifying, three‐dimensional model. A continuous discontinuity defect, involving both prisms and interprism, is a prominent feature of this type of Retzius lines. Prisms and interprism facing the deep aspect of the cleftlike defect show an enlarged, flat surface that encroaches on the cervically situated prisms being rebuilt from the same cleft. The initial part of a prism taking off from the cleft is of distorted shape. As the prism reaches the level of the interprism cleft, it abruptly regains its normal size and shape. The relationship between this type of Retzius lines and the carious process is discussed, and it is suggested that the discontinuity defect may retard the carious lesion due to a protective effect of its supposed organic content. The developmental events creating staircase‐type Retzius lines are discussed, and it is suggested that Tomes' processes are constricted near their bases with a corresponding increase in interprismatic growth region. Tomes' processes will have to reshape plastically as they move out of the constricted pits, trailing the parent ameloblasts as they resume enamel production and move in the direction of the prisms.
Normal variations in the relationship of the tricuspid valve to the membranous septum in the human heart
Authors: Restivo Angelo , Smith Audrey , Wilkinson James L. , Anderson Robert H. 
Published: February 2005

AbstractThe anatomy of the antero‐septal commissure of the tricuspid valve and its relationship to the membranous part of the septum are described in 72 normal hearts from subjects ranging in age from 25 weeks gestation to 13 months. Three major patterns were found. According to whether the contiguous leaflets were fused at the commissure, joined at the circumference of the orifice, or left a gap at the commissural site, the varieties are described as undivided, annular, or gap commissure, respectively. Commissures of annular type showed further morphological varieties, as did the patterns of division of the membranous septum into its atrioventricular and interventricular components. Dominance of the atrioventricular component and/or absence of the interventricular membranous septum were encountered in 38 cases out of 72 (52%). This finding demonstrates that dominance of the atrioventricular membranous septum during fetal life and infancy is not universal. The variability noted in the morphology and position of the antero‐septal commissure was not associated with other positional variations of the tricuspid valve.
Calcification capacity of dental papilla mesenchymal cells transplanted in the isogenic mouse spleen
Authors: Ishizeki Kiyoto , Nawa Tokio , Sugawara Mitsutaka 
Published: February 2005

AbstractThe capacity of the dental pulp to form calcified tissue was examined in papilla cells dissociated from first molar tooth germs of the neonatal mouse and isografted in the spleen for up to 7 days. To obtain papilla cell populations without odontoblasts, pulpal mesenchyme was isolated mechanically from the enamel organ after 0.1% trypsin treatment and rolled on a membrane filter. On day 3 after transplantation, the grafted papilla cells had changed into large, spindle‐shaped cells, and initial calcification with needle‐like crystals began in association with the collageneous matrix surrounding those cells. On day 7 after transplantation, the spindle cells transformed into odontoblast‐like cells containing well‐developed secretory organelles, and irregular, but nontubular, calcified tissues were commonly observed surrounding the extracellular collagenous matrix. The calcified tissue matrix with cellular inclusions displayed a structure similar to that of osteodentin. During this period, an intense positive reaction for alkaline phosphatase (ALPase) activity was demonstrated along the cell membranes of the odontoblast‐like cells aligned at the periphery of forming calcified tissue. Enzymatic activity could not be detected on the cells incorporated completely into osteodentin‐like matrix. The present results show that the papilla cell population transplanted into the spleen formed osteodentin‐like material, thus demonstrating the capacity of papilla cells to produce calcified tissue.
Vascular network in papillae of dog oral mucosa using corrosive resin casts with scanning electron microscopy
Authors: Kishi Yoshiaki , Takahashi Kazuto , Trowbridge Henry 
Published: February 2005

AbstractThe purpose of this study was to undertake a three‐dimensional analysis of the vascular network of the lamina propria in the gingiva, alveolar mucosa, buccal mucosa, palate, and lingual mucosa of the dog. Using the corrosive resin casting technique, casts of the vascular network were prepared and examined by scanning electron microscopy.In the oral mucosa, larger arteries in the submucosa divide into smaller branches that enter the lamina propria. These branches form one or more layers of vessels at the base of the papillae of the lamina propria, the so‐called subpapillary vascular network. Here the vessels divide again and enter the papillae to form a subepithelial capillary network. The configuration of the capillary loops within each papilla of the lamina propria is determined by the shape of the papilla. The characteristic shape of the loops resembles a hairpin. The capillary loops in the lingual papillae are larger and more complex than capillary loops found elsewhere in the oral mucosa. The mucosa of the posterior portion of the hard palate, the soft palate, and the tongue contain many venous valves.
Combined time‐lapse cinematography and immuno‐electron microscopy
Authors: Balfour B. M. , Goscicka T. , MacKenzie J. L. , Gautam A. , Tate M. , Clark J. 
Published: February 2005

AbstractA method was developed to record interactions between mobile non‐adherent immunocytes by time‐lapse cinematography and then to study the same cells by immuno‐electron microscopy, using monoclonal antibodies against surface components. For this purpose a modified stage was designed to fit an inverted microscope. The attachment included a device to cool the culture chamber with N2 gas, a micro‐injector for monoclonal antibody and immuno‐gold treatment, and two pairs of washing needles to change the medium without disturbance. The technique was first employed to study the formation of aggregates around the antigen‐presenting cells in cultures containing cells from hyper‐immunized animals. Recently peripheral blood cells from normal subjects and patients with immune deficiency syndromes were stimulated with pokeweed mitogen, cluster formation was recorded, and the cells were processed for immuno‐electron microscopy.
Platelet membrane skeleton revealed by quick‐freeze deep‐etch
Authors: Bearer Elaine L. 
Published: February 2005

AbstractActin polymerization is an essential component of platelet activation. Since actin appears to polymerize at its membrane‐associated end, knowledge of the structural relationship of actin filaments to membrane is an important part of understanding that polymerization process. A membrane‐associated actincontaining cytoskeleton has been described in human platelets biochemically and is composed, at least in part, by an association between glycoprotein Ib and the actin‐binding protein originally isolated from macrophages. Many other actinassociated proteins with known sub‐membranous localization in other systems have been found in platelets, including alpha‐actinin, vinculin, and low levels of spectrin and the red cell protein Band 4.1. Because of the density of the platelet cytoplasm, the structure of the membrane‐skeleton has not yet been visualized. We have used quick freeze‐deep etch techniques to observe the sub‐membranous cytoplasm and report visualization of a periodic, submembranous filament system not before seen in the platelet. This filamentous system was more easily observed in thrombin‐stimulated platelets, but appeared to be present in resting, discoid cells as well. The filaments could also be readily observed when platelets are lysed after fixation, stained with tannic acid, and embedded for thin‐sectioning. This membrane cytoskeleton was composed of 9 nm thick filaments lying 15 nm apart, and 15 nm from the membrane. The filaments appeared to lie in parallel and to encircle the cell. Similar filaments could be seen associated with intracytoplasmic membrane systems in activated cells.
Renin immunohistochemistry in the adrenal gland of the mouse fetus and neonate
Authors: Kon Yashuhiro , Hashimoto Yoshiharu , Kitagawa Hiroshi , Sugimura Makoto , Murakami Kazuo 
Published: February 2005

AbstractThe development of renin‐containing cells in fetal and neonatal adrenal glands of the mouse was studied using immunohistochemistry. On days 13–14 of gestation, immunoreactivity for renin was first observed in a few cortical cells of the gland, appearing as small patchy or granular reaction products in the perikaryon. The mitotic configurations of the cells demonstrating immunoreactivity were noted. On day 16 of gestation, a number of intensively immunoreactive cells were distributed in the aortal side of the cortical zone. On day 18 of gestation, and day 1 postparturition, a small number of potent immunoreactive cells were still found in the cortical area. Immunoreactivity of the cytoplasm was observed in the cells, some showing an intensive reaction and other possessing numerous tiny granules just below the cell membrane. On days 3, 5, and 7 after birth, no renincontaining cells were found in the adrenal gland. The ratio of the numbers of renin‐positive cells in certain areas to the numbers in the entire cortical area was significantly increased on day 16 of gestation, but there was no sexual difference in the ratios. The ratios were decreased subsequently until day 1 after birth. The possible significance of renin synthesis in specific adrenal cells in fetal life is discussed with respect to an important involvement of angiotensin II in the morphogenesis of the adrenal gland of the mouse.
Cadmium toxicity to the cornea of pregnant rats: Electron microscopy and x‐ray microanalysis
Authors: Yoshizuka Mitsuaki , McCarthy Kevin J. , Kaye Gordon I. , Fujimoto Sunao 
Published: February 2005

AbstractCadmium toxicity to the cornea of pregnant rats was studied using the electron microscope and x‐ray microanalyzer. In in‐vivo experiments, severe corneal edema occurred in pregnant dams that received intraperitoneal injections of cadmium sulphate for 4 days during gestation, but not in nonpregnant rats. Prominent swelling of mitochondria and the occurrence of intra‐ and inter‐cellular vacuoles in the corneal endothelium were observed only in pregnant dams.In in‐vitro experiments, electron‐dense deposits consiting of cadmium‐oxine complexes were preferentially found in swollen mitochondria of the endothelial cells. Cadmium peaks were obtained from these deposits with x‐ray microanalysis.These data suggest that the corneal edema observed after administration of cadmium may imply the disturbance of pump function and barrier function of the corneal endothelium due to the primary toxic effects of this metal on mitochondria.
Migration of fetal intestinal intervillous cells in neonatal mice
Authors: Calvert Raymond , Pothier Pierre 
Published: February 2005

AbstractThe migration of intestinal intervillous epithelial cells labeled in the fetus was followed in neonatal mice. At 17 days of gestation, a first group pregnant mice received three intraperitoneal injections of 3H‐thymidine (150 μCi/injection) administered at 30 min intervals. Two mothers were sacrificed 3 hours after the first injection. Mice from different litters were also sacrificed on days 0, 2, 4, 8, 12, 14, and 16 after birth. A second group of pregnant mice was injected at 18½ days of gestation and offspring were sacrificed on days 6, 8, 10, 12, 14, and 16 after birth. Segments of duodenum and ileum were fixed in glutaraldehyde, postfixed in osmium tetroxide, dehydrated, and embedded in Epon. Sections were stained with aldehyde fuchsin and processed for radioautography. By following the leading front and trailing edge of labeled cells in the longest villi of the duodenum and ileum, we observed that 1) extrusion zones become active immediately after birth and 2) the longest villi do not elongate until 10 days after birth in the duodenum and 14 days in the ileum, that is, when all labeled epithelial cells originally present in the fetus have been extruded. Moreover, by measuring the distance between the internal limit of the inner circular layer of smooth muscle and the intervillous epithelium at 17 days of gestation (12.95 ± 1.18 μm) or the bottom of the crypts at day 3 (14.81 ± 0.91μm), we propose that crypts do not develop as downgrowth: rather the intervillous epithelium is reshaped and the crypt‐villus junction moves upward, away from the muscularis externa.In conclusion, by analyzing the growth pattern of the longest villi in neonatal mice, we have found that a steady state between cell production and cell extrusion is reached at birth in the duodenum and by day 4 in the ileum. This steady state will be lost however, after day 10, thus enabling lengthening of the villi.
Cells resembling intraventricular macrophages are present in the subretinal space of human foetal eyes
Authors: McMenamin Paul G. , Loeffler Karin U. 
Published: February 2005

AbstractThe subretinal spaces (SRS) in 17 human foetal eyes were investigated by light microscopy and scanning and transmission electron microscopy. A hitherto undocumented group of pleomorphic cells was detected on the apical surface of the retinal pigment epithelium (RPE) and on the undersurface of the neural retina. These cells formed a regularly spaced array in the peripheral SRS, particularly in the most anterior portion nearest the ciliary body anlage. The morphology of the SRS cells ranged from a small round or ovoid from with a few short basal pseudopodia to an extremely flattened dendritic form. Ultrastructural features, such as large melanophagolysosomes, consistent with a phagocytic function, were observed in some cells. These SRS cells bore remarkable resemblance to epiplexus and supraependymal cells, considered to be the resident population of macrophages on the ventricular surfaces of the brain. This morphological parallelism, together with the anatomically homologous location, is strong evidence that SRS cells represent a normal population of macrophages in the developing human eye. No features consitent with an RPE or neuronal origin were observed. The possible role of these cells as transient phagocytes in the SRS with a possible destiny as retinal microglia is discussed.
Morphogenesis of the frontal organ in Bufo bufo during development
Authors: Farnesi R. M. , Tei S. , Vagnetti D. , Di Rosa I. , Fagotti A. , Santarella B. 
Published: February 2005

AbstractMorphogenesis of the frontal organ in Bufo bufo was examined under transmission electron microscope. Many remarkable similarities to the frontal organ of other Amphibia Anura are observed. It originates from a diverticulum in the dorsal region of the neural tube. It is egg‐shaped, has an eccentric lumen, and is made up of three kinds of cells: 1) photoreceptors, which protrude into the lumen; 2) supportive cells; and 3) ganglion cells, which make synaptic contact with the photoreceptors. Peculiar to Bufo bufo is the melanin‐like pigments around the light‐sensitive part of the photoreceptors. These pigments may prevent light dispersion. The frontal organ in Bufo bufo starts degenerating during the early premetamorphic stages.