bluuebunny/crossref_metadata_2025_split huggingface dataset:
Satellite cell response in rat soleus muscle undergoing hypertrophy due to surgical ablation of synergists
Authors: Snow Mikel H. 
Published: February 2005

AbstractAlthough the role of satellite cells has been confirmed during skeletal muscle growth and regeneration, their involvement during work‐induced muscle growth remains uncertain. In this study, chronically overloaded rat soleus muscles were ultrastructurally monitored following surgical ablation of synergists to examine cytological adaptations of satellite cells and myofibers. The left soleus muscle of 20 female Spague‐Dawley rats (7 weeks of age) was induced to hypertrophy by excising the contralateral plantaris and gastrocnemius muscles under pentobarbital anesthesia. Right limbs were sham‐operated and served as controls. On days 3, 7, 14, 21, and 30 after surgery, the soleus muscles were removed and processed for electron microscopy. Two morphologically distinct phases were noted in the surgically overloaded muscles. The first stage (week 1) was characterized by a significant increase in the number of satellite cells, and by more than half of the experimental muscle fibers displaying myofibrillar disruptions, mitochondrial alterations and glycogen pooling. The second phase (weeks 2–4) featured mostly normal, although larger appearing muscle fibers, with the satellite cell frequency remaining slightly elevated. These findings suggest that muscle fiber structural abnormalities, rather than an increase in muscle activity, may play a more significant role in the early activation of satellite cells during compensatory hypertrophy, whereas activation of satellite cells during the later stages may be in response to increased levels of muscle activity.
Spatial distribution of “tissue‐specific” antigens in the developing human heart and skeletal muscle. I. An immunohistochemical analysis of creatine kinase isoenzyme expression patterns
Authors: Wessels A. , Vermeulen J. L. M. , Virágh S. Z. , Kálmán F. , Morris G. E. , Man Nguyen Thi , Lamers W. H. , Moorman A. F. M. 
Published: February 2005

AbstractUsing monoclonal antibodies against the M and B subunit isoforms of creatine kinase (CK) we have investigated their distribution in developing human skeletal and cardiac muscle immunohistochemically. It is demonstrated that in skeletal muscle, a switch from CK‐B to CK‐M takes place around the week 8 of development, whereas in the developing heart, CK‐M is the predominant isoform from the earliest stage examined onward (i.e., 4½ weeks of development). In all hearts examined, local differences in concentration of the CK isoforms are observed. The CK‐M expression in the developing outflow tract (OFT) and conduction system is described in detail. Between the weeks 5 and 7 of development, the distal portion of the OFT is characterized by low CK‐M expression, whereas around the week 8–10 of development the myocardium around the developing semilunar valves in the OFT expresses a very high level of CK‐M. At all stages examined, a relatively low CK‐M level is observed in those regions in which the “slow” components of the conduction system do develop (e.g., the sinoatrial junction and atrioventricular junction), whereas a relatively high concentration of CK‐M is observed in those areas that are destined to become the “fast” components, i.e., the subendocardial myocardium of the ventricles. The high expression of CK‐M in the developing “fast components” of the conduction system contrasts with the relatively low expression of CK‐M in the force‐producing myocardium of the interventricular septum and free ventricular wall.
Effects of purified Pasteurella multocida dermonecrotoxin on cartilage and bone of the nasal ventral conchae of the piglet
Authors: Martineau‐Doizé Beatrice , Frantz Joseph C. , Martineau Guy‐Pierre 
Published: February 2005

AbstractThe effect of intramuscular injection of purified dermonecrotoxin (DNT) from Pasteurella multocida type D on the nasal ventral conchae of piglets was studied. Severe atrophy of the conchae was observed 4, 6, and 10 days after injection (p.i.d.). Lesions were observed in conchae cartilage and bone. Cartilage changes observed were the absence of chondrocyte maturation and hypertrophy, hyaline cartilage invasion by fibroblast‐like and multinucleated cells, and endothelium damage with haemorrhages along the cartilage. Intramembranous bone was absent on p.i.d. 4, 6, and 10. Lamellar bone trabeculae were rarefied on p.i.d. 4 and almost absent on p.i.d. 10. Trabeculae were either normal or had the aspect of a dissolved bone matrix, leaving only irregularly oriented collagen fiber bundles. The number of osteoclasts was increased, especially the subperiosteal osteo‐clasts at the eccentric side of the scrolls. The osteoblasts appeared normal or their cytoplasm was dilated by vacuoles. It is concluded that the macroscopic conchae atrophy results from histological alterations and subsequent loss of both cartilage and bone. Further investigation is necessary to know whether the toxic effect of DNT on cells and matrix is direct or dependent of the vascular damage.
Ultrastructural study of lamellar and nucleolus‐like bodies in the harderian gland during postnatal development of the hamster (Mesocricetus auratus)
Authors: López J. M. , Tolivia J. , Díaz C. , Alvarez‐Uría M. 
Published: February 2005

AbstractMembranous structures identified as lamellar bodies (LBs) and dense intracytoplasmic bodies referred to as nucleolus‐like bodies (NLBs) have been found in the hamster Harderian gland during neonatal stages. Both structures appear between 8 and 12 postnatal days, coinciding with the beginning of secretory activity. LBs in males and NLBs in both sexes gradually decrease in number with further differentiation of the glandular cells. The morphological features of these cytoplasmic structures are described, and their origin as well as their possible functional significance are discussed.
Ultrastructural evidence of mature Leydig cells and Leydig cell regression in the neonatal human testis
Authors: Prince Frederick P. 
Published: February 2005

AbstractThe neonatal period in male development is characterized by an acute rise in serum testosterone, which peaks at 2 to 3 months of age. The purpose of this study is to examine the neonatal human testicular interstitium at 4 months for evidence of Leydig cell maturation, as well as any morphological criteria relating to the fate of Leydig cells during this period, specifically, for signs of cell regression.Leydig cells are described with impressive development of the steroid secreting apparatus, which are consistent with the mature Leydig cells found during early fetal development and in the adult. The outstanding feature of these cells is the “organelle association” of extensive, anastamosing tubules of smooth endoplasmic reticulum (SER), pleomorphic mitochondria with a component of tubular cristae, and abundant microperoxisomes associated with the SER. Well‐developed Golgi elements, regionalized RER, and diverse cell inclusions are also characteristics of these cells. Reinke crystals and paracrystalline inclusions are absent. Gap junctions are common in this system and are notable in the asymmetric nature of the adjacent cytoplasmic components.These findings provide a morphologic correlate to the reported neonatal phase of testosterone production in man.Intermediate forms of Leydig cells are described with “organelle associations” including decreased SER with increased lipid droplets, and decreased SER with prominent cytoplasmic filaments and/or dramatic mitochondrial changes supportive of mitochondrial involution. Cells consistent with immature Leydig cells are also present. The rather impressive diversity in cell morphology present during this time frame of 4 months, slightly past the peak in testosterone production, provides evidence of Leydig cell regression and a continuity of the mature neonatal Leydig cells with the immature Leydig cells of childhood (Prince, 1984). There is also some evidence of cell degeneration.Although the developmental history of Leydig cells has been described for years as biphasic, it is time to view Leydig cell development in man as a triphasic event, fetal, neonatal, and pubertal.
Effects of maternal bilateral ureteral ligation on the development of the proximal tubule of the kidney in fetal rats: Morphometry and electron microscopic study
Authors: Okada Toshiya , Morikawa Yoshio 
Published: February 2005

AbstractDevelopment of the proximal tubule in the fetal kidney was studied following ligation of both ureters of pregnant rats. The ligation was performed on days 15, 17, 19, and 21 of gestation and autopsy followed 24 hours after each operation. On fetal days 20 and 22, the proximal tubular length per unit volume (1 mm3) of whole kidney of the fetuses from the ligatd mothers was significantly increased, while the ratio of total glomerular volume to total proximal tubular volume, was remarkably decreased when compared to that of the fetuses from the non‐ligated mothers. Apical vacuoles in proximal tubular cells were increased by the ligation on fetal days 20 and 22. These findings suggest that maternal bilateral ureteral ligation accelerates the growth and differentiation of the proximal tubule in fetal kidney, when the fetal kidney is functional in urine production.
Premitotic DNA synthesis in the brain of the adult frog (Rana esculenta L.): An autoradiographic 3H‐thymidine study
Authors: Bernocchi Graziella , Scherini Elda , Giacometti Silvia , Mareš Vladislav 
Published: February 2005

AbstractReplicative synthesis of DNA in the brain of the adult frog was studied by light microscope autoradiography. Animals collected during the active period (May–June) and in hibernation (January) were used. In active frogs, 3H‐thymidine labelling occurred mainly in the ependymal cells which line the ventricles. The mean labelling index (LI%) was higher in the ependyma of the lateral and fourth ventricles than in the ependyma of the lateral diencephalon and tectal parts of the mesencephalon. In the recessus infundibularis and preopticus the number of labelled cells (LCs) was several times greater than in the lateral parts of the third ventricle. LCs were seen subependymally only occasionally. The incidence of LCs in the parenchyma of the brain was much lower in most regions than in the ventricular ependyma; LCs were mainly small and, from their nuclear morphology, they were glial cells. The LI% reached the highest value in the septum hippocampi and in the nucleus entopeduncularis. In these locations, LCs were larger and closer in size to the nerve cells of these regions. From comparison with data obtained earlier in the brain of mammals, it is evident that the distribution of proliferating cells in the olfactory and limbic system is phylogenetically conservative. The occurrence of pyknotic cells in the same areas which contain LCs, suggests that cell division reflects in part the process of cell renewal observed in mammals. However, proliferating cells could also be linked to the continuous growth observed in non‐mammalian vertebrates. In hibernating frogs, LCs and pyknoses were not seen or were found occasionally, which further indicates the functional significance of both processes.
Turnover of asymmetric unit membranes in the transitional epithelial superficial cells of the rat urinary bladder
Authors: Amano Osamu , Kataoka Seiki , Yamamoto Toshi Yuki 
Published: February 2005

AbstractAsymmetric thick unit membranes were observed on the luminal surface, fusiform vesicles, and multivesicular bodies of superficial cells of rat transitional epithelium. When HRP‐labeled Ricinus communis lectin (RCA‐I) was injected into the rat urinary bladder, RCA‐I was deposited along the luminal cell membrane and in some multivesicular bodies, but not in the fusiform vesicles either before or after contraction. When the bladder was sliced by Vibratome and stained with HRP‐labeled RCA‐I after fixation, RCA‐I was observed in many cell organelles, including fusiform vesicles and multivesicular bodies as well as the luminal surface. When small pieces of tissue were stained en‐bloc with HRP‐labeled RCA‐I, RCA‐I was found along the luminal cell surface but not in the fusiform vesicles nor the multivesicular bodies. When HRP alone was injected into the bladder, HRP was observed in some multivesicular bodies after contraction but not in the fusiform vesicles. Various lysosomes were observed by electron microscopy. Some were wrapping multivesicular bodies in ringlike fashion, and some contained asymmetric unit membranes. These findings suggest that the asymmetric unit membranes are carried to the luminal cell membrane via the fusiform vesicles and that old luminal cell membranes are removed via the multivesicular bodies to be degraded by lysosomes.
A new technique for explantation and in vitro cultivation of chicken embryos
Authors: Dugan John D. , Lawton Michael T. , Glaser Bert , Brem Henry 
Published: February 2005

AbstractA technique is described for explanting and cultivating chicken embryos in plastic drinking cups which have been modified with plastic wrap to reproduce the geometry and dimensions of the egg shell. Successful explantation rates of 97% are possible with a double‐window technique, and survivability in cups exceeds that achievable in other in vitro systems (i.e., petri dishes). Longterm survival to the 21st day of incubation is seen routinely. This system with cups is less expensive than that with petri dishes, and simpler than that with plastic wrap/tripods. Thus, this new method of in vitro cultivation of chicken embryos improves upon explantation rate, survivability and system design, and has a wide range of applications in developmental biology, angiogenesis, cancer, and pharmacology research.
The effects of age on atrophy and recovery in denervated fiber types of the rat nasolabialis muscle
Authors: White Ketti K. , Vaughan Deborah W. 
Published: February 2005

AbstractThis study investigates the effects of advancing age on responses of nasolabialis muscle fibers to denervation and reinnervation. The nasolabialis is innervated by the facial nerve and is responsible for the whisking movement of the animal's large vibrissae. In young adult (3‐month) and middle‐aged (15‐month) rats the muscle on one side of the head was denervated by crushing the facial nerve. At specific days postcrush, animals were sacrificed and thick sections of muscle were incubated to demonstrate cytochrome oxidase activity, a mitochondrial enzyme, which differentiated between red, white, and intermediate fiber types. The rate and extent of atrophy and recovery were evaluated using light microscope morphometric methods for which transverse fiber areas were measured and compared to fibers on the contralateral control side. There was an age‐related delay in the time of functional return since older animals resumed normal whisking behavior 6 days later than the younger animals. In both age groups, white and intermediate fibers atrophied to the greatest extent and red fibers showed least atrophy. Despite the different responses of the fiber types to denervation, there was no age difference in the maximum degree of fiber atrophy within each fiber type. Age differences did occur in the rate of the denervation response since the middle‐aged fibers consistantly showed a more rapid significant atrophy than the young adult fibers. During recovery, older fibers may be limited in their ability to attain the size of fibers on the control side. The results indicate that through middle age, the process of advancing age increases the susceptibility of the nasolabialis muscle to denervation but does not alter the maximum extent of atrophy. The ability to recover to normal fiber size, at least 2 months after denervation, is also age‐related.
Fiducial points for three‐dimensional computer‐assisted reconstruction of serial light microscopic sections of umbilical cord
Authors: Ongaro Ivano , Sperber Geoffrey H. , Machin Geoffrey A. , Murdoch Colleen A. 
Published: February 2005

AbstractFascicles of human sural (peripheral sensory) nerve were used as external fiducial points (FP) for accurate registration of serial light microscopic sections in three‐dimensional reconstruction of human umbilical cord. This paper describes a method for embedding the FPs within the paraffin wax block simultaneously with the specimen to be sectioned. Using a new design of embedding box, the FPs are embedded close to the specimen and are transferred to the slides as part of the tissue sections. Three to four FPs were used to align and scale the serial tissue sections for digitization and computerized reconstruction, using a commercially available software program on IBM‐compatible 80386 hardware. A three‐dimensional solid surface graphic model of a segment of human umbilical cord was generated.
Rearrangement of the metaphyseal vasculature of the rat growth plate in rickets and rachitic reversal: A model of vascular arrest and angiogenesis renewed
Authors: Hunter William L. , Arsenault A. Larry , Hodsman Anthony B. 
Published: February 2005

AbstractThe morphology of the metaphyseal microvasculature at the epiphysis was examined at both the light and electron microscopic level in rickets and rachitic reversal. The animals studied were normal, rachitic, and rachitic reversed at 8, 24, and 96 hours post‐vitamin D administration. The overall architecture of the metaphyseal vessels was significantly altered throughout the intervals examined. In the rachitic animal, arterioles, venules, and capillaries were found adjacent to the growth plate, either directly apposed to the hypertrophic chondrocytes or separated from them by bone‐forming cells. These vessels are in many ways similar to the larger arterioles and venules that normally supply the metaphyseal capillary sprouts, but in the normal growing animal are usually located 350–500 μm from the epiphyseal cartilage. The rachitic capillaries appear relatively well differentiated with a partial basement membrane and a perivascular cell lining. In early rachitic reversal, small vascular projections are induced to grow from the large diameter venules that border upon the hypertrophic chondrocytes. These vascular sprouts that invade the epiphyseal cartilage are quite undifferentiated, with no basement membrane or pericyte lining at the sprout apex and occasional abluminal endothelial cell projections. Within 96 hours, the metaphyseal microvasculature has returned to an apparently normal state with only capillaries at the cartilage‐vascular interface and larger vessels (arterioles and venules) located several hundred microns deeper into the metaphysis. The sequential processes of differentiation and cessation of capillary growth followed by dedifferentiation and reinitiation of microvascular growth make the rachitic system a unique one in which to study angiogenesis.
Spatiotemporal pattern of type X collagen gene expression and collagen deposition in embryonic chick vertebrae undergoing endochondral ossification
Authors: Iyama Ken‐Ichi , Ninomiya Yoshifumi , Olsen Bjorn R. , Linsenmayer Thomas F. , Trelstad Robert L. , Hayashi Masando 
Published: February 2005

AbstractWe examined the spatio‐temporal pattern of type X collagen mRNA and its protein in the embryonic chick vertebrae undergoing ossification by in situ hybridization and immunohistochemistry. Hypertrophic chondrocytes, producing type X collagen, were developed as islands of cells in a few vertebral body segments of stage 36 embryos. These cells were increased in number at stages 37 and 38 and they expressed high levels of type X collagen mRNA and deposited its protein in the matrix. Blood vessels entered from the perichondrium at stage 37 and invaded deeply into hypertrophic cartilage at stage 38. As the vertebrae grew further at stage 40, the leading front of active hypertrophic chondrocytes with high levels of type X mRNA shifted from the midvertebral perivascular area towards intervertebral borders, while the perivascular area retained a number of inactive hypertrophic chondrocytes with low levels of type X mRNA. Type X collagen was found in large amounts throughout the matrix areas containing both active and inactive hypertrophic chondrocytes. Calcium was detected by von Kossa's technique in hypertrophic cartilage matrix in a small amount at stage 37, in parts of the matrix with type X collagen deposition in succeeding stages, and finally in almost the entire area of type X collagen deposition at stage 45. The vertebral segments of stage 45 embryos also showed a clearly reversed pattern of expression between type X collagen mRNA and types II and IX collagen mRNAs. The results demonstrate that the production of type X collagen by hypertrophic chondrocytes precedes both vascular invasion and mineralization of the matrix, suggesting that hypertrophic chondrocytes have an important role in regulating these events.
Ultrastructure of the turtle spermatozoon
Authors: Hess Rex A. , Thurston Ronald J. , Gist Daniel H. 
Published: February 2005

AbstractThe turtle spermatozoon is vermiform in shape with a narrow pointed head that is curved. In general, the turtle sperm contains a typical head, midpiece and tail, similar in morphology to that of birds, amphibians and other reptiles. However, several structures are unique. These unusual features include (1) a perforatorial cap over the proximal end of the nucleus, which contains 2–3 rods that are contiguous with intranuclear tubules; (2) a connecting collar of dense material that surrounds the base of the nucleus; (3) a distal centriole containing central microtubules that extend its entire length and having outer triplicate microtubules that open toward the central cavity of the centriole; and (4) unusual spherical mitochondria containing 7–8 outer laminated membranes.
Ultrastructure of lingual salivary glands in the American chameleon: Anolis carolinensis
Authors: Rabinowitz Terry , Tandler Bernard 
Published: February 2005

AbstractThat portion of the dorsal surface of the tongue of Anolis carolinensis that is covered by plumose papillae is underlaid by a series of tubular salivary glands that open between the papillae; glands persist into the posterior zone of the tongue, where they open between cylindriform papillae. Anterior glands are serous in nature—they consist of simple columnar epithelial cells that contain abundant secretory granules exhibiting a variety of substructural patterns. The Golgi apparatus is large and of unusual appearance, with numerous closely packed terminal dilatations and condensing vacuoles. Near the posterior border of the lingual zone covered by plumose papillae, mucous cells begin to appear in the glandular epithelium. More posteriorly, the apical portions of the glands consist entirely of mucous cells, whereas the blind ends of the glands are composed of serous cells. The most posterior glands are of the pure mucous variety. The glands finally disappear a short distance posterior to the cylindriform papillae. The functions of the abundant and highly differentiated salivary glands of the Anolis tongue remain obscure.