bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chorda tympani innervation of anterior mandibular taste buds in the chicken (Gallus gallus domesticus)
Authors: Ganchrow Judith R. , Ganchrow Donald , Oppenheimer Miriam 
Published: February 2005

AbstractWhile the mammalian chorda tympani innervates taste buds on the anterior two‐thirds of the tongue, the chorda tympani of chickens does not enter the tongue, but rather is reported to supply the oral epithelium of the lower beak subjacent to the tongue. This study in the chicken investigated whether the integrity of taste buds in the lower beak is normally dependent upon innervation by the chorda tympani. Following unilateral ligation and removal of a large section of the chorda tympani, animals were sacrificed at 11, 14, and 21 days postoperatively. Oral tissue between the lingual frenulum and beak tip was serially examined, and the presence of each bud was recorded, noting the point at which the bud opened into the oral cavity. No buds were observed on the operated side in any of the cases, while the average bud count on the unoperated side was 33 ± 10 (SD). On the unoperated side, taste buds were generally associated with anterior mandibular salivary gland ducts that reached surface epithelium and opened into the oral cavity. On the operated side, the cellular organization adjacent to gland ducts and in duct‐free epithelium appeared as in control (i.e., bud‐free) epithelium. The number of salivary gland duct openings into the oral cavity was equivalent on the operated and control sides. It is concluded that the chorda tympani of chickens innervates taste buds in the anterior lower beak epithelium and that it functions to maintain the structural integrity of these buds.
Papillary morphology of the tongue of the American chameleon:Anolis carolinensis
Authors: Rabinowitz Terry , Tandler Bernard 
Published: February 2005

AbstractBased on regional differences in surface morphology, the dorsum of the tongue ofAnolis carolinensiscan be subdivided into four distinct zones. The first quarter of the tongue is relatively smooth, whereas the second and fourth quarters are festooned with closely packed cylindriform papillae, which are covered by typical parakeratotic stratified squamous epithelium. The third quarter of the tongue is covered by papillae of novel morphology that we have named “plumose papillae.” These are composed of a slender connective tissue core covered by stratified squamous epithelium from whose surface numerous elongated cells radiate. These “plume cells” are about 30–40 μm long and have an extremely irregular nucleus in their expanded terminus. Their stalks are affixed by desmosomes to the deeper cells of the epithelium, and their free surfaces are covered by intricately patterned microplications. Their cytosol contains a dense web of 100‐Å cytofilaments that may be involved in maintaining the peculiar morphology of the cells. Regardless of type, all lingual papillae ofA. carolinensiscontain a single longitudinally oriented skeletal muscle fiber that originates from the underlying lingual muscles, raising the possibility that the papillae can be moved at will. The plumose papillae and their retinue of plume cells are unique morphological structures that may be important in mastication and deglutition of food.
Histochemical types and sizes of fibers in the rectus abdominis muscle of guinea pig: Adaptive response to pregnancy
Authors: Costerbosa G. Lalatta , Barazzoni A. M. , Lucchi M. L. , Bortolami R. 
Published: February 2005

AbstractEffects of pregnancy stimulation upon histochemically assessed myofibrillar ATPase and muscle fiber diameters were analysed in the rectus abdominis (RA) muscle of guinea pig. Samples of the muscle were taken at 30, 40, 50, 60, and 70 days of pregnancy and compared with samples of the same muscle taken from nonpregnant guinea pigs. Changes in muscle fiber proportions were noted through the course of pregnancy. Starting from 50 days of gestation an increase in type I fibers and a decrease in type IIB fibers were noted. Increase in muscle fiber diameters was also observed in type I, IIA, and IIB fibers. In addition, the RA muscle of the male guinea pig was compared with that of the female guinea pig and showed more type IIA and less type IIB fibers and all the three fiber types were larger than those of the female.
Automatic morphometric analysis of skeletal muscle fibers in the aging man
Authors: Poggi Paola , Marchetti Carla , Scelsi Roberto 
Published: February 2005

AbstractA qualitative and quantitative analysis of M. vastus lateralis fibers from 40 male sedentary subjects, ranging in age from 30 to 89 years, was carried out by light and electron microscopy and by an automatic Interactive Image Analysis System. Biopsies for enzyme histochemical and ultrastructural studies were taken from subjects subdivided into four age groups: 30–50, 60–70, 71–80, and 81–89 years. Attention was focused on the fiber type size and distribution, the size and the amount of mitochondria, and the amount of lipid droplets. Main changes observed in the four age groups are indicative of a sequence of events within senescent skeletal muscle fibers. With increasing age the enzyme histochemical reactions reveal changes in fiber type distribution characterized by decrease in muscle fiber diameter and by type I fiber predominance.Type II fiber atrophy is consistent. Type I fiber predominance seen in older subjects could be related to a selective decrease of type II fibers with age. It also suggests a possible conversion of type II fibers to type I fibers. Lipid droplet percentage per fiber area increases, while mitochondrial size and mitochondrial percentage per fiber area decrease with age. It is possible that energy requirements decline with age and that the decrease in mitochondrial size and percentage represents a response to a reduced metabolic demand.
Development of wing‐bud‐derived muscles in normal and wingless chick embryos: A computer‐assisted three‐dimensional reconstruction study of muscle pattern formation in the absence of skeletal elements
Authors: Lanser Mark E. , Fallon John F. 
Published: February 2005

AbstractThe mechanisms whereby the normal pattern of muscles within the developing chick limb bud is generated are largely unexplored. It has been proposed that the muscle pattern is established independently of the pattern for the limb skeletal elements to which the muscles normally attach (Shellswell and Wolpert: “The Pattern of Muscle and Tendon Development in the Chick Wing.” In: Vertebrate Limb and Somite Morphogenesis. Cambridge University Press, Cambridge, pp. 71–86, 1977). To further examine this possibility we studied the formation of the proximal wing muscles in normal and wingless chick embryos. The muscles of the shoulder region (including the pectoralis) arise as part of the dorsal and ventral premuscle masses of the developing limb bud. These secondarily migrate out of the limb to take origin from the pectoral girdle while inserting onto the humerus (Sullivan: Aust. J. Zool., 10:458–516, 1962). With rare exceptions, wingless embryos have complete absence of wing skeletal elements, but they may possess more than 40% of the normal volume of wing‐bud‐derived muscles. The muscles that remain in wingless embryos are primarily shoulder muscles, and to a varying extent, the pectoralis. The question we sought to answer was whether in wingless embryos the proximal wing muscles could form a normal pattern in the absence of the humerus and distal wing skeletal elements. By examining three‐dimensional reconstructions of the proximal wing region in normal and wingless embryos, we found that the initial subdivision of the dorsal and ventral premuscle masses proceeded normally in the absence of the wing skeleton. This resulted in a grossly normal pattern of proximal wing muscles despite the absence of wing skeletal elements. However, some subsequent cleavages of individual muscles within premuscle mass divisions did not occur in wingless embryos. This suggests that the skeleton may be required for this step in muscle morphogenesis to occur. We also observed that the wing‐budderived muscles in wingless embryos were nearly always anchored to the pectoral girdle at both ends. Sometimes this resulted in muscles making abnormal tendonous fusions with other muscles derived from the opposite (i.e., dorsal or ventral) premuscle mass. Therefore, attachment to the skeleton may be important for some facet of muscle development. Finally, the supracoracoideus muscle was absent in all but one wingless embryo we examined in the present study. In that one, it was substantially reduced in volume compared to normal. Despite the absence of this muscle, the space normally occupied by the supracoracoideus was maintained beneath the pectoralis. This observation suggests that the form, or shape, of a muscle may be established within the connective tissue in the absence of the muscle itself.
Distinct types of encapsulated sensory corpuscles in the oral mucosa of the dog: Immunohistochemical and electron microscopic studies
Authors: Tachibana T. , Ishizeki K. , Sakakura Y. 
Published: February 2005

AbstractThe types, structure, and distribution of encapsulated sensory endings that have lamellar investments in the oral mucosa and vermilion border of the lip of adult dogs were studied by light and electron microscopy. Immunohistochemistry for cholinesterase was used to identify the corpuscules by light microscopy. Two different types of corpuscular end‐organs containing definite inner cores were distinguished. One was a typical, simple corpuscle, which contains only one, but sometimes two, inner cores composed of densely piled cytoplasmic lamellae surrounding a central axon terminal. The other type was characterized by the coexistence of convoluted inner cores, arborized free endings, and thin nerve bundles within a perineural capsule; we term this type “compound corpuscle.” The ultrastructure of the inner cores in compound corpuscles was similar to that of mature, simple corpuscles. The arborized free endings in the compound corpuscles usually contained an accumulation of mitochondria and small clear vesicles. The compound corpuscles were frequently encountered in the vermilion border of the lip and in the labial and buccal mucosae but were rare in the masticatory mucosa of the gingiva and hard palate. From the results, it was concluded that the compound corpuscle is a distinct type of the sensory end‐organ containing inner cores.
Regulation of the density of spermatogonia in the seminiferous epithelium of the Chinese hamster: II. Differentiating spermatogonia
Authors: De Rooij D. G. , Lok D. 
Published: February 2005

AbstractIn this study the yield of the proliferation of the differentiating spermatogonia into spermatocytes was determined in five Chinese hamsters. Large differences of up to a factor 2 were found between the numbers of A1 spermatogonia in the various animals. However, the numbers of leptotene spermatocytes varied only by up to a factor 1.2 between animals. It is concluded that more spermatogonial degeneration takes place in animals with a relatively large number of A1 spermatogonia than in those with a small number of these cells. In such a way in all animals ultimately about the same number of spermatocytes is formed.An experiment was done in which the number of A1 spermatogonia was lowered with the S‐phase killer cytosine arabinoside (Ara‐C). It was found that this greatly increased the yield of the spermatogonial proliferation, showing a direct relationship between the number of A1 spermatogonia in an animal and the extent of the spermatogonial degeneration.In addition to the variation in the number of A1 spermatogonia found between various animals, an even larger variation of up to a factor 3.7 was found between the numbers of A1 spermatogonia in different areas of seminiferous tubules within each animal. Nevertheless the variation in the number of leptotene spermatocytes in different areas within each animal was not larger than a factor 1.3. It is concluded that in the normal animal the phenomenon of spermatogonial degeneration depends on the local density of these spermatogonia. Apparently, when too many spermatogonia are present the surplus of cells degenerates.
Morphologic and histochemical analysis of the newt (Notophthalmus viridescens) liver
Authors: Goldblatt Peter J. , Hampton James A. , DiDio Lydia N. , Skeel Kristi A. , Klaunig James E. 
Published: February 2005

AbstractArchitectural arrangement, ultrastructure, and selected histochemical properties of the newt (Notophthalmus viridescens) liver were examined. Although hematopoietic tissue (1–4 cells thick) invested the liver, direct vascular communication between this tissue and hepatic parenchyma was not observed. The liver was intensely positive when stained with Oil‐red‐O and periodic acid‐Schiff reagent and connective tissue was limited to large vascular channels and the capsule. A distinctive polarity was observed in the hepatic vascular system when lobes were viewed in cross section. Dorsally, portal venules accompanied arterioles and branches of the biliary system, while tributaries of hepatic veins were observed ventrally. Following perfusion fixation, hepatocytes appeared as sheets of cells 1–5 cells thick; however, lobules as defined in adult mammalian liver were absent. Hepatocytes contained abundant smooth endoplasmic reticulum, mitochondria, electron‐dense lysosomes, patches of granular endoplasmic reticulum, and lipid droplets. Continuous endothelial cells lined sinusoids and exhibited fenestrae organized into structures similar to sieve plates observed in mammalian liver. Variable numbers of melanin‐containing macrophages and subendothelial macrophages were observed; however, Kupffer cells and lipid containing perisinusoidal fat‐storing cells were not seen. Patterns of reaction product for glucose‐6‐phosphatase (G‐6‐Pase), glucose‐6‐phosphate dehydrogenase (G‐6‐PDH), and succinic dehydrogenase (SDH) were localized in the newt liver. All enzymes exhibited a uniform distribution pattern; however, small punctate regions of intensely positive G‐6‐PDH cells were noted within hepatic parenchyma. Cells comprising the hematopoietic tissue were intensely positive for G‐6‐Pase, G‐6‐PHD, and negative for SDH.
Appearance of the cyst‐ or ductule‐like structures and their role in the restoration of the rat pituitary autograft
Authors: Gon Gotetsu , Shirasawa Nobuyuki , Ishikawa Hiroshi 
Published: February 2005

AbstractThe anterior pituitary glands of 31‐day‐old male rats were autotransplanted under renal capsule. At the 3rd and 5th day after transplantation, the autografts were observed by electron microscopy and by immunohistochemistry using antiserum against S‐100 protein, which serves as marker of folliculo‐stellate (FS) cells.On the 3rd day, a large part of the graft was replaced with loose connective tissue in which the FS cells were remarkable in number. The FS cells encircled a small number of granular cells and formed cyst‐ or ductule‐like structures with neighboring FS cells. Together, FS cells and the encircled granular cells formed a basement membrane surrounding the entire ductule. Throughout the regenerating gland, many such ductules were found. On the 5th day, both granular cells and FS cells increased in number.The above observations suggest that FS cells may play an important role in the restoration of degenerated pituitary glandular tissues during the early stage of the transplantation.
Distribution of actin in spermatids and adjacent sertoli cell regions of the rat
Authors: Masri B. A. , Russell L. D. , Vogl A. W. 
Published: February 2005

AbstractIn this study, we describe the distribution of actin filaments in and around spermatids that are mechanically dissociated, in the presence and absence of exogenous trypsin, from the seminiferous epithelium of the rat. NBD‐phallacidin and subfragment 1 of the myosin molecule (S‐1) are used as probes for filamentous actin at the light and electron microscopic levels, respectively.The fluorescence associated with spermatids mechanically dissociated in the absence of trypsin is due to actin both in the spermatogenic cells themselves and in attached Sertoli cell ectoplasmic specializations. Fluorescence generated by labelled actin in ectoplasmic specializations occurs in linear tracts that follow the outer contour of spermatid heads. The residual flourescence seen when trypsin is used to detach Sertoli cell fragments is diffuse and due to f‐actin in the subacrosomal space. Electron microscopic data agree with the fluorescence results.This study conclusively demonstrates that Sertoli cell ectoplasmic specializations remain attached to spermatids mechanically dissociated from the seminiferous epithelium. This observation may be useful when attempting to isolate ectoplasmic specializations for biochemical analyses.
Neovascularization in the pre‐ and postnatal rabbit corpora cavernosa penis: Light and electron microscopy and autoradiography
Authors: Fujimoto Sunao , Yamamoto Koji , Kagawa Hirohiko , Yoshizuka Mitsuaki , Nomiyama Tomohiko , Maruyama Takeshi 
Published: February 2005

AbstractIn the late prenatal stage, the rabbit corpora cavernosa penis (cavernous bodies) are occupied by a large number of mesenchymal cells actively proliferating by mitosis. Most profiles of the cavernous sinuses show growing capillaries consisting of immature endothelial cells and enclosing a narrow lumen. Such growing capillaries are often associated with the mesenchymal cells that contact with each other and eventually with the endothelial cells.Between 1 and 7 postnatal days, the capillary network develops extensively and the maturation of the capillaries results in a flattened endothelium with a continuous basal lamina. The mesenchymal cells are also associated with the helicine arterial sprouts at this time period. No endothelial mitotic figures were observed within the growing capillaries in pre‐ and postnatal specimens examined.Single pulse labeling with 3H‐thymidine in the postnatal rabbits demonstrates that the labeled endothelial cells of the growing capillaries increase in number at 48 hours after injection compared with those at 24 hours, whereas the labeled mesenchymal cells inversely decrease in number.These findings indicate that the incorporation of the mesenchymal cells as vesselforming cells into the growing capillaries accelerates the neovascularization in the rabbit cavernous bodies.
The elasmobranch renal corpuscle: Fine structure of Bowman's capsule and the glomerular capillary wall
Authors: Lacy Eric R. , Castellucci Mario , Reale Enrico 
Published: February 2005

AbstractThe fine structure of the renal corpuscle of the marine elasmobranch fish, the little skate (Raja erinacea), and two species of dogfish sharks, the spiny dogfish (Squalus acanthias) and the smooth dogfish (Mustelus canis), was studied by light microscopy and by transmission (thin sections, freeze‐fracture replicas) and scanning electron microscopy. Bowman's capsule was lined by ciliated cells, similar to those of the first part of the tubule, at the urinary pole and squamous cells in the zone between urinary and vascular poles. At the vascular pole the visceral epithelial cells had some closely apposed cuboidal cell bodies with a few processes inserted along the basement membrane, but foot processes were absent. These cuboidal cells were continuous with podocytes, which had primary, secondary and tertiary processes from which the pedicels arose. An inconsistently present slit membrane bridged the pedicels at varying distance from the urinary space. Small maculae and large fasciae occludentes joined the podocytes and/or their processes among which gap junctions were observed. In the skate kidney, the podocyte plasma membrane facing the basement membrane contained orthogonal arrays of particles. The epithelial basement membrane of the glomeruli in all elasmobranchs was consistently thick. The mesangial cells were numerous and partially enveloped in a basement membrane; their long processes almost compeletely circumscribed the capillary walls. The mesangial matrix was abundant and consisted of loosely arranged collagen fibrils, microfibrils and occasional anchoring fibrils. The endothelial cells had irregularly distributed fenestrations of various sizes and lay on their discontinuous basement membrane which was separate from that under the epithelial cells. The filtration apparatus resembles that of immature mammals and lower vertebrates.
Unusual example of a persistent stapedial artery in a human
Authors: Diamond Michael K. 
Published: February 2005

AbstractA complete dissection of a persistent stapedial artery and its companion venous sinuses revealed several noteworthy features. 1) The proximal portion of the stapedial artery stem was missing, and the entire stapedial system was supplied through an anastomosis between the occipital artery and the ramus posterior of the stapedial artery; a similar type of collateral supply occurs in some xenarthrans and bats. The ramus posterior is a component of the primitive eutherian stapedial system and one that has not been reported previously in a primate. 2) Both the anterior and posterior divisions of the ramus superior were present. The posterior division is identified here for the first time in a primate. 3) The anterior and posterior divisions were accompanied by the cranio‐obital and petrosquamous sinuses, respectively. These sinuses were incomplete and attenuated relative to the primitive eutherian condition.
Endocytosis and vesicular traffic in fetal and adult colonic goblet cells
Authors: Colony Pamela C. , Specian Robert D. 
Published: February 2005

AbstractStructural and functional differences between adult and fetal colonic goblet cells have not been clearly defined. To compare the binding, uptake, and intracellular pathway of internalized apical membrane in fetal and adult goblet cells, cationic ferritin (CF) was used as a nonspecific probe. The initial distribution of membrane anionic sites was determined in segments of proximal and distal colon from fetal (18–22 days) and adult rats that were fixed prior to a 10‐minute exposure to CF at 4°C. Uniform binding along the apical membrane and microvilli was noted at all ages. To assess uptake and intracellular transport, segments of proximal and distal colon from fetal and adult rats were exposed to CF for 10 minutes at 4°C prior to a saline wash and incubation in saline or Liebovitz L‐15 medium for 3, 6, 15, 30, or 60 minutes at 37°C. In addition, fetal rats between 18 and 22 days gestation (birth) were exposed to CF continuously for 10–30 minutes via an intracaecal injection. The results showed extensive uptake of CF in the fetal goblet cells and a more variable intracellular pathway than in with the adult. Within 3 minutes, numerous CF positive vesicles and tubules were present within the apical cytoplasm as well as interspersed among the secretory granules of the fetal goblet cell. Most of these vesicles were smooth surfaced, although some were coated. By 15 minutes, CF was frequently seen in multivesicular bodies, and occasionally in vacuoles in the vicinity of the Golgi. No CF was detected in Golgi cisternae. In contrast to fetal cells, only limited uptake was noted in adult goblet cells and the vesicles were restricted to the periphery of the secretory granule mass. In addition, transport to lysosomes was the exclusive route of these vesicles in the adult. These findings indicate that vesicular uptake is extensive in fetal goblet cells and the intracellular pathway is more variable and less restricted than in the adult.