bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunocytochemical localization of sulfated glycoprotein‐1 (SGP‐1) and identification of its transcripts in epithelial cells of the extratesticular duct system of the rat
Authors: Hermo L. , Morales C. , Oko R. 
Published: February 2005

AbstractThe localization of sulfated glycoprotein‐1 (SGP‐1) in the extratesticular duct system was analyzed using an affinity purified antibody raised against the protein in conjunction with light (LM) and electron (EM) microscope immunocytochemistry. In the LM an intense immunoperoxidase reaction product was observed over the cytoplasm of Sertoli cells as well as over the tails of late spermatids. The rete epithelial cells and noncilliated cells of the efferent ducts also showed an intense uniform reaction over their entire cytoplasm. In the EM, immunogold labeling was noted over the entire endocytic apparatus of these cells including coated pits, endosomes, multivesicular bodies, and secondary lysosomes. Since there was no labeling of the luminal contents including sperm along the epididymis, it was concluded that the Sertoli‐derived SGP‐1 must dissociate from the sperm and be taken up by epithelial cells at the level of the rete testis and efferent ducts.In all regions of the epididymis, except the cauda, the principal cells showed, in the LM, an intense reaction over bodies of various shapes and sizes in their supranuclear region; this corresponded in the EM to a strong immunogold labeling of secondary lysosomes. No labeling was noted, however, over coated pits, endosomes, or pale multivesicular bodies, suggesting that SGP‐1 was not being endocytosed from the lumen. Similar observations were noted for the epithelial clear cells along the entire epididymis. In the cauda epididymidis, principal cells presented a weak immunolabeling of their secondary lysosomes.Northern blot analysis revealed a strong 2.6 Kb band corresponding to the mRNA of SGP‐1 in the efferent ducts and all regions of the epididymis with the exception of the cauda. Coincident with the mRNA expression of SGP‐1 it was found that small clusters of gold particles representing anti SGP‐1, presumably membrane bound, were associated with the Golgi apparatus as well as in close proximity to secondary lysosomes. There was, however, no evidence for the secretion of SGP‐1 into the lumen. These results suggest that SGP‐1 is synthesized by the epithelial cells of the male duct system and ferried by small vesicles derived from the Golgi apparatus to secondary lysosomes. Because SGP‐1 has recently been shown to have substantial sequence similarity to prosaposin, it may be speculated that SGP‐1 is instrumental in the degradation of membrane glycolipids present within secondary lysosomes of epithelial cells of the extratesticular duct system.
Blind‐ending tubules and branching patterns of the rat ductuli efferentes
Authors: Guttroff Robert F. , Cooke Paul S. , Hess Rex A. 
Published: February 2005

AbstractThe ductuli efferentes of Sprague‐Dawley rats were studied by microdissection and microscopic evaluation to document the presence of blindending tubules (ductuli aberrantes) and to describe morphological and ultrastructural differences between normally open ductules and blind‐ending tubules. The branching patterns of the ductuli efferentes varied considerably between animals. A majority of the animals studied had either six or seven ductuli connected to the rete testis, with some animals having as few as four or as many as eight. Pairs of ductules began merging in the conus vasculosa, ultimately forming a single terminal duct within the capsule of the initial segment epididymidis. In a majority of animals, the junctions were unequally matched and located at various positions within the conus. Blind‐ending tubules, found in 60% of the animals, were surrounded by thick connective tissue, and had a smaller diameter (78.7 ± 1.4 μm) than normal ductules in the conus vasculosa (119.5 ± 2.1 μm) or the terminus (102.2 ± 1.5 μm). The lumina of blind‐ending tubules were contracted and did not contain sperm. Nonciliated cells in the epithelium of blind‐ending tubules contained fewer PAS‐positive granules and electron‐dense bodies (lysosomes) than nonciliated cells in normal ductules. Consideration of these characteristics will prevent blind‐ending tubules from being mistaken for pathological changes in efferent ductules.
Early development of the human area postrema and subfornical organ
Authors: Castañeyra‐Perdomo A. , Meyer G. , Heylings D. J. 
Published: February 2005

AbstractThe first appearance and early development of two circumventricular organs, the area postrema (AP) and the subfornical organ (SFO), were investigated in human embryos and fetuses from the 4th to the 40th gestational weeks (GW). The AP appears very early in development, during the GW 10; its high vascularization can be seen from GW14, and differentiated neurons are observed from GW 16. The SFO is characterized by a late onset of development. It can first be distinguished at GW 17, but it does not attain cytological differentiation until the last weeks of gestation. It is suggested that the AP has important functions during fetal life, which are related to normal fetal weight and growth; in contrast the SFO, which is connected with drinking behavior and salt/water balance, seems to play a less essential role in early fetal life.
Histochemical study of the heart of the axolotl (Ambystoma mexicanum)
Authors: Melinek Rosemary , Mirolli Maurizio 
Published: February 2005

AbstractWe have investigated the presence of cells containing monoamines, substance P, and neuron‐specific enolase (NSE) in the heart and in the pericardial wall of a urodele amphibian, the axolotl. Fibers containing substance P‐like immunoreactivity were present in the heart but not in the pericardial wall. Also present in the heart were small branched cells, which stained metachromatically with toluidine blue. Similar cells were found in the peritoneum and were tentatively identified as mast cells. NSE‐immunoreactive fibers were found both in the heart and in the pericardial wall. Small intensely fluorescent (SIF) cells of the pericardial wall contained a high concentration of norepinephrine but no other monoamines, substance P, or NSE. Comparison with data available for the mudpuppy, Necturus maculosus, a closely related amphibian species, suggests that the innervation of the heart in the axolotl is substantially different. © 1992 Wiley‐Liss, Inc.
Localization of actin, α‐actinin, and tropomyosin in bovine spermatozoa and epididymal epithelium
Authors: Yagi Ahmed , Paranko Jorma 
Published: February 2005

AbstractActin, α‐actinin, and tropomyosin were localized in the testicular, epididymal, and ejaculated spermatozoa and in the epithelium of the bovine epididymis by means of specific antibodies using an indirect immunofluorescence technique. Immunocytochemical results were confirmed by the western blot analysis. Independent of the method of fixation, washing, or sonication, actin, α‐actinin, and tropomyosin were all consistently localized in the neck of the spermatozoa. Actin and tropomyosin present in the postacrosomal area could be removed by sonication, whereas α‐actinin in the basal plate appeared to be resistant to the treatment. In the unwashed spermatozoa α‐actinin‐specific immunofluorescence was seen over the acrosomal area, whereas in the washed sperm it appeared as a narrow cap at the margin of the head. In the latter location, its distribution was similar to that of tropomyosin. In the majority of preparations, tropomyosin could be localized in the principal piece of the tail. Even though some actin‐specific immunofluorescence could be identified in the principal piece of the tail of the testicular and epididymal spermatozoa, a strong immunoreaction appeared only in the ejaculated spermatozoa. In the principal cells of the epididymal epithelium, specific fluorescence for actin, α‐actinin, and tropomyosin occurred in the apical junctional complex. Basal bodies of the solitary cilia of the epididymal epithelium were labelled with antitropomyosin and anti‐α‐actinin antibodies. Besides offering new information about the cytoskeletal composition of the mammalian sperm, the present results support the hypothesized homology between the connecting piece of the sperm neck and the basal body of the cilia. © 1992 Wiley‐Liss, Inc.
Immunohistological analysis in the distribution of cells in the fetal porcine adenohypophysis
Authors: Sasaki Fumihiko , Ichikawa Yuji , Yamauchi Shoji 
Published: February 2005

AbstractAdenohypophyses of porcine fetuses from 25 to 110 days of gestation were studied by immunohistochemical staining to ascertain the ontogeny of specific cell types and their spatial distribution in the pars distalis. No hormonecontaining cells were found before 30 days of gestation. ACTH cells were observed first at 40 days, while GH and LH cells appeared first at 60 days. PRL cells were initially detected at 105 days. ACTH immunoreactive cells were also observed in the pars intermedia at 40 days.Blood capillaries were interposed between cell cords of the pars distalis after 40 days of gestation.ACTH cells were evenly distribution in all areas of the pars distalis except the rostal area (sex zone). GH cells were densely distributed in lateral wings of the pars distalis and immediately anterior to Rathke's lumen. PRL cells resembled GH cells in their distribution pattern, but PRL cells were fewer in number. LH cells were scattered in the sex zone of the pars distalis from 60 to 80 days of gestation. After 90 days, they became scattered throughout the pars distalis but were more numerous in the sex zone than in other areas.The inductive elements of adenohypophysial cells from Rathke's pouch epithelia are discussed. We hypothesize that cell cords of specific areas facing Rathke's lumen may differentiate into specific cell types of the pars distalis during fetal life. © 1992 Wiley‐Liss, Inc.
Cell kinetics of lamina propria fibroblasts in normal adult hamster bronchus
Authors: Zajicek G. , Breuer R. 
Published: February 2005

AbstractForty‐nine 12‐week‐old male Syrian golden hamsters (Mesocricetus auratus), weighing 108 to 128 g, were injected i. p. with [3H]‐thymidine (3HTdR 2 μCi/g body wt). Animals were divided into 7 weight‐matched groups and were killed at 1 hour (day zero) and 1, 2, 3, 4, 7, and 14 days after thymidine injection. Lungs were fixed by vascular perfusion of 4% formalin/1% glutaraldehyde in 0.2 M cacodylate buffer at pH 7.4, cut at 2 μm, dipped in Kodak NTB3 or NTB2 nuclear emulsion, exposed for 2 weeks, developed and stained. In each airway cross‐section, total epithelial and fibroblast counts and labeled cell count were estimated. A cell was considered labeled when 3 or more silver grains appeared on its nucleus. The background grain count was less than 1 grain per nucleus.Mean epithelial and fibroblast cell density in a 100 μm segment were respectively 14.8 ± 0.1 and 6.6 ± 0.1 cells (the second number is one standard error of the mean). One hour after labeling, their respective labeling indices (L. I.) were 0.13 ± 0.02 and 1.24 ± 0.1. On day 1, their L. I. doubled and then returned to the initial value. One hour after labeling, epithelial and fibroblast mean grain counts did not differ significantly. They were respectively 20.6 + 1, and 15.8 ± 2. Because grain count intensity is closely related to DNA synthetic time, it seems plausible that epithelial and fibroblast synthetic times do not differ much. Cell turnover and cell cycle times were estimated from grain count dilution curves. The respective loggrain dilution slopes, ‐0.025 ± 0.005 and ‐0.044 ± 0.014 do not differ significatly when tested by t‐test. It is concluded, therefore, that both cell types turn over at the same rate with an estimated cell cycle time of 20 days. © 1992 Wiley‐Liss, Inc.
Immunolocalization of enamel proteins during amelogenesis in the cat
Authors: Nanci A. , McKee M. D. , Smith C. E. 
Published: February 2005

AbstractAmelogenesis in the cat has been suggested to closely resemble enamel formation in human teeth. In order to further characterize the sequence of events leading to enamel formation in the cat, the expression and distribution of enamel proteins throughout amelogenisis were examined by postembedding immunocytochemistry using an antibody to mouse amelogenins and the high resolution protein A‐gold technique. Enamel proteins were first immunodetected in ameloblasts and in the extracellular matrix during the presecretory stage. Secretory stage ameloblasts showed the most intense cellular reactivity. In these cells, protein synthetic organelles, secretory granules, and large lysosome‐like structures were all intensely labeled. Extracellulary, numerous gold particles were observed over enamel and over patches of material found at the baso‐lateral surfaces of these ameloblasts. During the early maturation stage, the protein synthetic organelles and secretory granules of ameloblasts still showed some immunoreactivity, although the most conspicuous labeling at this later stage was found over enamel and over material present amoung the extensive apical membrane infoldings of ruffle‐ended ameloblasts. Qualitative analysis of lysosome‐like elements in ameloblasts suggested that their frequency and immunoreactivity in the maturation stage were relatively lower than in the secretory stage, where some groups of cells often showed numerous large labeled structures. The enamel matrix was intensely labeled at all stages; however, cervical‐occlusal and surface‐depth gradients were readily apparent by conventional staining and by quantitative analysis of immunolabeling in the late secretory and early maturation stages. These data suggest that the cellular and extracellular distribution of enamel proteins in the cat is generally similar to that reported in other species, although some particularities were observed, perhaps reflecting variation in the timing of developmental parameters. © 1992 Wiley‐Liss, Inc.
Development of cartilage and bone tissues of the anterior part of the mandible in cichlid fish: A light and TEM study
Authors: Huysseune Ann , Sire Jean‐Yves 
Published: February 2005

AbstractThe present paper presents ultrastructural details of chondrogenesis of Meckel's cartilage and of ossification of its associated peri‐ and parachondral bones in a teleost fish, the cichlid Hemichromis bimaculatus. We have distinguished four stages during chondrogenesis, each of which is characterized by specific cellular and matrix features: blastema, primordium, differentiated cartilage and cartilage surrounded by perichondral bone. The blastema is characterized by prechondroblasts and the lack of cartilage matrix; the primordium by chondroblasts and the onset of secretion of matrix of fibrillar and granular nature; differentiated cartilage is characterized by chondrocytes and larger amounts of typical hyaline cartilage matrix. Once perichondral bone is laid down, the chondrocytes show degenerative features but not true hypertrophy. Differentiation of the cartilage cells is attended with cytoplasmic changes indicative of an increasing secretory activity. There is a regional calcification of the cartilage matrix by fusion of calcospherites. Chondrogenesis of the symphyseal area is continuous with that of the rami but starts slightly later. Formation of perichondral bone at the cartilage surface is attended with the deposition of a transitional zone apparently containing a mixture of the two matrices. The role of the perichondral cells is discussed and it is proposed that they may contribute to the formation of the two matrices. The transitional zone may then result either from a diffusion process or from the simultaneous deposition of elements of the two matrices. Growth of the cartilage is argued to be largely the result of matrix secretion, except in the symphyseal area where appositional growth probably occurs until the region is completely covered by perichondral bone. This paper provides a basis for further studies on the developmental interactions between cartilage, bone and teeth during mandibular development in cichlids. © 1992 Wiley‐Liss, Inc.
Development of the human sphenomandibular ligament
Authors: Vazquez J. F. Rodriguez , Velasco J. R. Merida , Collado J. Jimenez 
Published: February 2005

AbstractThe development and arrangement of the sphenomandibular ligament of 60 human embryos and fetuses were studied. Meckel's cartilage appeared as a single, continuous fibrous structure lying between the mandibular lingula and the malleus of the middle ear in fetuses of 210 mm crown‐rump length (22 weeks of age) and over. This structure constitutes the malleolomandibular ligament, and two clearly differentiated portions bound by the tympanosquamosal fissure could be seen: a juxtaarticular portion, inserted on the posterior edge of the interpterygoid aponeurosis, and a tympanic portion, onto which the disc of the temporomandibular joint inserted. Some of the authors consider that if tension is applied to the sphenomandibular ligament this may injure the middle ear. The anatomical arrangement of the sphenomandibular ligament could explain these injuries. © 1992 Wiley‐Liss, Inc.
Cytochemical localization of dipeptidyl peptidase II activity in rat incisor tooth ameloblasts
Authors: Smid J. R. , Monsour P. A. , Rousseau E. M. , Young W. G. 
Published: February 2005

AbstractDipeptidyl peptidase II (DPP II), E.C. 3.4.14.2, a serine class endopeptidase, is widely used as a lysosomal marker in cytochemical studies. To date most ultrastructural studies of ameloblasts use the presence of acid phosphatase activity to identify cellular organelles to be lysosomal. Using decalcified rat mandibles, with kidney tissue as a positive control, DPP II activity, was assessed with specific substrate Lysyl‐alanine‐4‐methoxy‐2‐naphthylamide in ameloblasts at an ultrastructural level. Reaction product (RP) indicative of DPP II activity was observed only within lysosome‐like organelles. These RP‐labelled organelles were only localized in the supra‐ or para‐nuclear regions of the ameloblasts, which corresponds with previous studies using acid phosphatase cytochemistry. However, in contrast with these studies, RP was not detected in the distal region of the ameloblasts, viz., in the Tomes' processes of the secretory ameloblasts or near the ruffled border in the maturation ameloblasts. The transitional ameloblasts were notable for the intensity of staining of their RP‐labelled organelles. We propose that DPP II may have a role in programmed cell death which is thought to occur in this transition zone.Biochemical analysis of rat incisor enamel organ homogenates, indicated tissue fixation resulted in an 82% reduction in DPP II activity, although the specific activity of DPP II was not affected. © 1992 Wiley‐Liss, Inc.
Demonstration of amelogenin in the enamel‐free cusps of rat molar tooth germs: Immunofluorescent and immunoelectron microscopic studies
Authors: Inai Tetsuichiro , Nagata Kengo , Kukita Toshio , Kurisu Kojiro 
Published: February 2005

AbstractThe enamel‐free cusps of 1–4‐day‐old rat mandibular first molars were investigated using the monoclonal antibody En3 against rat amelogenin at light and electron microscopic levels in order to clarify whether the enamel‐free cusp is virtually devoid of enamel.At 1 day after birth, there were presecretory ameloblast‐like cells (PALCs), which were short and were not polarized, at the cusp tips. They were close to the outer enamel epithelium. Hematoxylin positive enamel matrix was not distinctly observed in the enamel‐free cusp by light microscopy, but almost continuous immunofluorescence for amelogenin was detected at the interface between PALCs and dentin. The penetration of immunopositive material toward the dental pulp was also observed in the enamel‐free cusp.At 4 day after birth, both in the frontal section and in the horizontal section, almost continuous immunofluorescence was recognized at the interface between PALCs and dentin in the enamel‐free cusp. The penetration of amelogenin toward the dental pulp was not seen in the enamel‐free cusp. By immunoelectron microscopy, immunolabelling was recognized in the Golgi apparatus of PALCs, in a layer of amorphous material at the interface between PALCs and dentin, and in stippled material‐like substance in the intercellular space between PALCs. Although no basement membrane was observed beneath PALCs, they did not have Tomes' processes.These investigations suggest that PALCs in the enamel‐free cusp differentiate into the secretory cells and that they can synthesize and secrete the amorphous material containing amelogenin at the interface between PALCs and dentin. The penetration of amelogenin toward the dental pulp might play a role in the interaction between PALCs and odontoblasts in the enamel‐free cusp and/or the initiation of mineralization of predentin. © 1992 Wiley‐Liss, Inc.
Selective lectin‐binding sites of primordial germ cells in chick and quail embryos
Authors: Yoshinaga Kazuya , Fujimoto Toyoaki , Nakamura Masao , Terakura Hirotsugu 
Published: February 2005

AbstractTo ascertain the histochemical characteristics of surface carbohydrates on avian primordial germ cells (PGC), we examined the distribution of binding sites for several biotinylated lectins in chick and quail embryos. Some binding sites were detected almost selectively with PGC but not with other embryonic sites. Of these, lectin from Sojanum tuberosum (STA) reacted with PGC in both avian species, whereas lectin from Wistaria floribunda (WFA) and Griffonia simplicifolia II (GS‐II) reacted in the quail and the chick, respectively. The binding site for STA was found at the cell surface and cytoplasm of the PGC from their initial appearance in the germinal crescent through migration to sexually indifferent gonads, whereas the WFA reaction was seen at stages before and during migration. These reactivities showed most intensely on the surface of PGC at the peak of their migration. In contrast, GS‐II binding site was restricted to the cytoplasm, and its distribution was similar to that of the periodic acid‐Schiff (PAS)‐positive glycogen granules in chick PGC. These results suggest that some selective binding sites on the PGC surface play a significant role in their migration and show that lectins STA, WFA, and GS‐II can be used as probes for identification of the avian PGC. © 1992 Wiley‐Liss, Inc.
Plastic embedding procedure for 15 μm sections of large undecalcified tissue blocks
Authors: Lataster L. M. A. , Van Mameren H. , Terwindt E. 
Published: February 2005

AbstractA method is described that produces sections (15 μm) of large specimens (with dimensions up to 140 × 100 × 200 mm). They are suitable for comparison to CT images of that specimen and can be used as a basis for three dimensional reconstructions.Frozen unfixed parts of the human body are embedded in polyurethane and scanned with CT. Undecalcified slices, 6 mm thick, of these specimens are cut with a bandsaw. These slices are successfully embedded in polyester resin by means of fixation, dehydration, and subsequent impregnation with this resin. Sections of 15 μm are obtained by cutting the trimmed and sandpapered polyester blocks with an LKB multirange microtome. They are collected on adhesive tape and stained according to Weigert‐Azan, sealed between adhesive acetate sheets and photographed on colour slide film. As an example photographs of sections of the human elbow and lumbar spine region are presented. © 1992 Wiley‐Liss, Inc.