bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appearance of complex branched fibers following repetitive muscle trauma in normal rat skeletal muscle
Authors: Tamaki Tetsuro , Akatsuka Akira 
Published: February 2005

AbstractBackground: To examine whether the complex branched fibers observed in mdx mutant mice were formed in normal skeletal muscles, long‐term repetitive muscle trauma was applied to muscle of normal Wistar male rats.Methods: Three kinds of artificial muscle trauma—crush injury, bupivacaine hydrochloride treatment, and forced stretching of contracting muscle (eccentric contraction)—were performed once a week for 10 weeks to achieve a state of repetitive degeneration and regeneration in the muscles. Two weeks after the final treatment, numerical, histochemical, and three‐dimensional analyses by scanning electron microscopy were performed.Results: Mean numbers of total branched fibers of the three groups were increased compared with normal control values, especially in the bupivacaine treatment group (three‐ to fivefold greater than in the other two groups). Aggregations of fibers of the same type which usually appear in mdx mice were observed in various parts of histological sections of the bupivacaine treatment group and only in a part of the crush injury group. No aggregations were observed in sections of the forced stretching group. In the three‐dimensional analysis, complex branched fibers appearing as an “anastomosing syncytial reticulum” were observed only in the bupivacaine treatment group.Conclusions: These findings suggest that the formation of an anastomosing syncytial reticulum is one of the adaptation mechanisms of normal skeletal muscle rather than a specific event in mdx mutant mice, and long‐term repeated trauma of the same fiber is necessary for this formation. Adaptive changes in the muscles with the three different types of muscle trauma are discussed. © 1994 Wiley‐Liss, Inc.
Ultrastructural localization of lectin receptors in the preimplantation ovine embryo
Authors: De Paz P. , Sanchez A. J. , Fernandez J. G. , Garcia C. , Chamorro C. A. , Anel L. 
Published: February 2005

AbstractBackground: Preimplantation development of mammalia is characterized by cell surface changes functioning in intercellular communication and adhesion. The glycoconjugate role in cellular interactions has been analysed for several groups but not in sheep embryos. The binding patterns of eleven lectins during sheep preimplanatation development were investigated and the role of glycoconjugates in early development was discussed.Methods: Ultrathin sections from preimplantation ovine embryos (3–7 days) were incubated with different colloidal gold conjugated lectins and the frequency of gold particles on the cell membrane, some organelles, and the zona pellucida was evaluated.Results and Conclusions: We observed a higher staining of WGA, DBA, and SBA lectins in the intercellular contact zone with respect to the free cell surface of blastomeres during cleavage. This indicates that the N‐acetyl galactosamine and N‐acetyl glucosamine residues may be involved in sheep morula compaction. In contrast, the trophoblast cell displays an increase of staining of some lectins previously identified during cleavage (LcH, WGA, SBA, MPA, and PNA) on the free membrane, and a lack of sugar residues in the intercellular surface. This polarization of the trophoblast cell surface is not observed in the inner cell mass and could provide a mechanism for differentiation within the blastocyst. Intracytoplasmic vesicles show a cytochemical identity with lysosomes in the blastocyst (abundant GlcNAc and Man/Glc residues) that may reflect a functional relationship between both organelles in an intracellular cycle. The zona pellucida presents abundant GalNAc, GlcNAc, and Gal residues during preimplantation ovine development. © 1994 Wiley‐Liss, Inc.
Future directions in antler research
Authors: Goss Richard J. 
Published: February 2005

AbstractThrough a series of interrogatories, unsolved problems of antler evolution, anatomy, development, physiology, and pathology are probed, with commentaries on the following prospects for future research:
How could these improbable appendages have evolved mechanisms to commit suicide, jettison the corpse, and regenerate new ones every year?
By what developmental processes are antlers able to prescribe their own morphogenesis with mirror image accuracy year after year and in some cases produce deliberate asymmetries?
What causes the scalp to transform into velvet skin as a deer's first antlers develop?
Why do healing pedicle stumps give rise to antler buds instead of scar tissue?
How is the unprecedented rate of antler elongation related to the diameter and length of the structure to be grown?
How come wound healing by pedicle skin is held in abeyance for several months until new growth resumes?
How is it that tropical deer regenerate antlers at any time of year, while in temperate zones deer do so in seasonal unison?
How do deer find enough calcium to make such massive antlers in only a few months?
What is the nature of the bizarre tumors that some antlers grow following castration? © 1995 Wiley‐Liss, Inc.
Reticulo‐endothelial stroma of the head‐kidney from the seawater teleost gilthead seabream (Sparus aurata L.): An ultrastructural and cytochemical study
Authors: Meseguer José , López‐Ruiz Antonio , Garcí‐Ayala Alfonsa 
Published: February 2005

AbstractBackground: Head‐kidney, considered the major fish lympho‐haemopoietic tissue, consists of cells of the different haemopoietic series supported by a network of stromal cells whose morphofunctional properties have not been established. We report the ultrastructure and cytochemical features of the reticulo‐endothelial stroma of the head‐kidney from the seawater teleost gilthead seabream (Sparus aurata L.).Methods: Samples of head‐kidney were processed for electron microscopic study. Some of the samples were incubated for acid and alkaline phosphatase, peroxidase, glucose‐6‐phosphatase, or ATPase.Results: The reticulo‐endothelial stroma of gilthead seabream head‐kidney consists of sinusoidal cells (endothelial and adventitial cells) and reticular cells (macrophage‐type reticulum and fibroblast‐like reticular cells). Transcytosis vesicles and rounded medium electron‐dense granules were observed in the cytoplasm of the endothelial cells. The adventitial cells partially covered the outside surface of the endothelial cells and were joined by desmosomes. The macrophage‐type reticulum cells were characterized by their cytoplasmic processes and acid phosphatase positive lysosomes. The fibroblast‐like reticular cells were joined by desmosomes and formed an extensive network between the haemopoietic parenchyma. They were peroxidase negative and acid and alkaline phosphatase, glucose‐6‐phosphatase, β‐glucuronidase, and ATPase positive.Conclusions: The ultrastructural and cytochemical features of the reticulo‐endothelial stroma of the gilthead seabream head‐kidney are similar to those of mammalian bone marrow, suggesting phylogenetic analogies between both tissues. © 1995 Wiley‐Liss, Inc.
Proliferative activity by cell type in the developing rat parotid gland
Authors: Redman Robert S. 
Published: February 2005

AbstractBackground: In contrast to the considerable amount of research that has been done on the proliferative activity of the several types of parenchymal cells in the developing submandibular glands of rodents, systematic studies of cellular proliferation in the developing parotid gland have been confined to the acinar cells. The purpose of the present study was to attempt to fill this knowledge gap.Methods: Tritiated thymidine was parenterally administered to Sprague‐Dawley rats at ages representative of the pre‐ and postnatal development of the parotid gland, and glands were harvested for autoradiography 90 min after injection. Mitotic activity among all cell types was verified by electron microscopy.Results: At all ages, the % labeled cells was much greater among the acini than any other cell type, including well‐differentiated cells at 25 and 40 days. However, there were only small alterations in the proportions of cells comprised by the major cell types.Conclusions: Current theories on the histogenesis of salivary glands and their neoplasms are based on the renewing population model, in which both normal differentiated cells and neoplastic cells arise from undifferentiated stem cells in the ducts. However, these results suggest that most of the migration and redifferentiation in the developing rat parotid gland must be in the opposite direction, i.e., the acinar cells redifferentiate into ductal cells. They also indicate that until there are precise data on the rates of cell death among the several cell types, it remains more appropriate for salivary glands to be categorized as an expanding, rather than renewing, population. © 1995 Wiley‐Liss, Inc.
Lipocortin 1 in apoptosis: Mammary regression
Authors: McKanna James A. 
Published: February 2005

AbstractBackground: Enigmatically, degradation of debris generated in programmed cell death (apoptosis) elicits little inflammation. Having previously detected the upregulation of lipocortin 1 (LC1), a 35‐kDa protein with anti‐inflammatory and immuno‐suppressive properties, at sites of non‐inflammatory phagocytosis in the central nervous system (J Neurosci Res 36:491–500, 1993), we sought to determine if LC1 was involved in apoptosis.Methods: LC1 immunoreactivity in mammary glands of adult rats was quantified in situ using video microdensitometry before and during postlactational regression.Results: LC1 is present in the mammary ducts but is absent from the alveoli during lactation. One day after weaning, however, LC1 is detected in the lactiferous cells and, as apoptosis proceeds over the ensuing 4 days, total LC1 in the gland increases >10‐fold over resting levels. LC1 remains high in both the apoptotic cells and epithelial phagocytes through day 10, but the total LC1 per gland drops as the apoptotic cells are cleared.Conclusions: Published experiments have shown that LC1 specifically binds Ca++ and phosphatidylserine, and that these affinities are modulated by tyrosine phosphorylation and cross‐linking with transglutaminase. Thus, LC1 appears to be a candidate for several putative activities in apoptosis (e.g., phagocyte recognition via phosphatidylserine binding and/or buffering intracellular Ca++) in addition to its anti‐inflammatory role. © 1995 Wiley‐Liss, Inc.
Phenotype of dystrophinopathy in old MDX mice
Authors: Lefaucheur Jean Pascal , Pastoret Christian , Sebille Alain 
Published: February 2005

AbstractBackground: Mdx mutant mice, like patients with Duchenne Muscular Dystrophy (DMD), lack dystrophin, a subsarcolemmal protein, that results in myofiber necrosis. However young mdx mice, in contrast to DMD children, exhibit a successful muscle regeneration and not an extensive fibrosis.Methods: Old mdx mice were monitored clinically up to their spontaneous death, and most of their organs were studied histologically to look for differences with those of the wild C57BL/10 mice strain.Results: In old mdx mice (at least 20 months of age), we report clinical and pathological features of muscular dystrophy, i.e., progressive motor weakness and loss of myofibers replaced by extensive connective tissue, similar to the phenotype of dystrophinopathy observed in DMD patients. Various degrees of dystrophic involvement were observed in cardiac, respiratory, postural, and hindlimb skeletal mdx muscles and also in smooth muscles of the digestive and urinary tracts. No gross histological abnormalities were found in other tissue than muscular tissue.Conclusions: Late in life, mdx mice develop a muscular dystrophy close to DMD dystrophinopathy. We suggest that the study of the effects of ageing in mdx mice would give clues to better understand the pathophysiology of DMD. © 1995 Wiley‐Liss, Inc.
T‐dependent areas in the chicken bursa of fabricius: An immunohistological study
Authors: Cortés Alfonso , Fonfría Jose , Vicente Angeles , Varas Alberto , Moreno Javier , Zapata Agustín G. 
Published: February 2005

AbstractBackground: The so‐called diffusely infiltrated lymphoid tissue of the chicken bursa of Fabricius was previously described as a T‐dependent bursal area.Methods: We have analyzed immunohistologically its postnatal development by using a battery of mAbs, most of them raised specifically to chicken T cells, in order to characterize phenotypically the nature of its cell components, appearance, development, and possible functional significance.Results: Our results demonstrate that this tissue represents poorly developed lymphoid aggregates, the cell content reminiscent of that found in other lymphoid tissues occurring throughout the avian gut. The first lymphoid elements appear in this bursal area only after hatchin, growing rapidly to reach the adult condition in the second week of postnatal life. They consist mainly of T lymphocytes, including principally CD4+ TcRαVβ1+ cells, which form cell groups and CD8+ cells, and TcRγδ+ lymphocytes, which predominate in the subepithelial area and within the epithelium. MHC Class II molecule‐expressing cells and IgM‐, IgG‐, and IgA‐positive B lymphocytes also occupy the subepithelial region.Conclusions: We propose that the bursal diffusely infiltrated lymphoid tissue of the chicken represents gut‐associated lymphoid tissue involved in mounting immune responses to antigens that reach the bursal lumen via the cloaca. © 1995 Wiley‐Liss, Inc.
Immunocytochemical localization of tyrosine hydroxylase and gamma‐aminobutyric acid in the mesencephalic trigeminal nucleus of the cat: A light and electron microscopic study
Authors: Lazarov Nikolai E. , Chouchkov Christo N. 
Published: February 2005

AbstractBackground: Recent studies conducted on the rat have demonstrated that the mesencephalic trigeminal nucleus (MTN) neurons, involved in the proprioceptive transmission, contain some neuroactive substances, including classical and amino acid neurotransmitters. In addition, there is evidence that serotonin could not act as a neurotransmitter at the first synaptic relay in the cat MTN. In the present study, we aimed to examine two other possible neurotransmitter systems, i.e., catecholamines and gamma‐aminobutyric acid (GABA), and the relationships between GABA‐immunoreactive (IR) neurons and tyrosine hydroxylase (TH)‐IR axonal varicosities in the MTN of the cat.Methods: To ensure the localization of immunoreactive structures, the experiments were carried out at the light and electron microscopic level using single immunostaining for TH and GABA alone. The correlation between GABA‐IR cell bodies and TH‐IR fibers was investigated by means of double‐labeling immunogold and peroxidase technique for GABA and TH.Results: Light microscopically, a few GABA‐IR neurons were observed in the cat MTN. These small‐size, labeled cells, most likely interneurons, were apposed to unstained large mesencephalic trigeminal cells. Most of the large nonreactive MTN neurons were closely surrounded by fine TH‐IR varicose or nonvaricose fibers and dot‐like structures, presumably nerve terminals. Under the electron microscope, TH‐IR fibers were not seen in synaptic contact and only rarely appeared to be in close proximity to neuronal profiles of small GABAergic cells, which contained gold particles.Conclusions: Taken together with earlier studies from other laboratories, the present findings suggest that GABAergic system might play an indirect role in the proprioceptive information processing in the cat MTN by interactions of GABA‐immunoreactive neurons with the systems that control the transmission of selected sensory information. In contrast, the presence of TH‐IR fibers in direct apposition to the majority of MTN neurons provide further evidence that presumed GABAergic interneurons have extensive interactions with catecholamine varicosities and raise the possibility that catecholamines could modify the transmission on these neurons. © 1995 Wiley‐Liss, Inc.
Agonadal presumptive XX/XY leukochimeric pig
Authors: Clarkson B. G. , Fisher K. R. S. , Partlow G. D. 
Published: February 2005

AbstractBackground: XX/XY chimeric pigs are uncommon and their reproductive anatomy is variable and unpredictable.Method: A piglet was identified by its enlarged vulva as a possible intersex. Venous blood was collected at 1.5 and 9 months for karyotyping and determination of testosterone and estrone sulphate concentrations. At 1 year euthanasia was performed. The reproductive tract was carefully dissected and examined histologically.Results: As the animal matured the vulva did not develop relative to the size of the animal. Lymphocyte cultures indicated a 70% XX/30% XY chimera. The reproductive tract consisted of a strand of tissue enveloped by fascia. Histological study revealed presumptive Wolffian derivatives, coiled bilateral ducts along the tract, and a Müllerian derivative, a medially located duct in the caudal third of the tract. No gonads were found. Plasma levels of estrone sulfate and testosterone were negligible.Conclusions: In utero exposure to exogenous androgens from a male cotwin or weak endogenous adrenal androgens may account for the enlarged vulva at birth and retention of the androgen dependent Wolffian duct primordia. An atesticular state is supported by retention of the Müllerian duct primordia and the negligible peripheral sex steroids. © 1995 Wiley‐Liss, Inc.
Immunoelectron microscopic localization of galectin‐3, an IgE binding protein, in human mast cells and basophils
Authors: Craig Shirley S. , Krishnaswamy Priya , Irani Anne‐Marie A. , Kepley Christopher L. , Liu Fu‐Tong , Schwartz Lawrence B. 
Published: February 2005

AbstractGalectin‐3 is an endogenous soluble lectin within the family called galectins that bind β‐galactosides. Homologs of the protein isolated from different sources were previously designated as IgE‐binding protein (ϵBP), CBP35, CPB30, Mac‐2, RL‐29, RLL, L‐29, and HL‐29. All are now renamed galectin‐3. This lectin is widely distributed in cells and tissues of mice, rats, dogs, hamsters, and humans.Light microscopic immunohistochemistry and ultrastructural immunogold labeling methods were used to determine the distribution of galectin‐3 in human mast cells of several organs, in mast cells developed in vitro from human fetal liver cells, and in human peripheral blood basophils. Immunolabeling for the protein was observed in mast cells from all sources and in basophils. The lectin was detected in the nucleus and/or the cytoplasm. The nuclear labeling was over heterochromatin whereas euchromatin was unlabeled. Cytoplasmic labeling was concentrated over secretory granules. The intensity of staining generally was greater in mast cells of skin when compared with that of mast cells in other locations and with that of basophils. Studies have indicated that in mast cells galectin‐3 may be involved in promoting their adhesion to basal laminae. In this study the localization of galectin‐3 in the secretory granules of human mast cells and basophils suggests that these cells may release this lectin when activated to degranulate. © 1995 Wiley‐Liss, Inc.
Alveolar bone turnover in male rats: Site‐ and age‐specific changes
Authors: King G. J. , Latta L. , Rutenberg J. , Ossi A. , Keeling S. D. 
Published: February 2005

AbstractBackground: This study compares alveolar bone turnover adjacent to distally drifting maxillary first molar teeth of rapidly and slowly growing rats. Methods: Two groups of forty male rats (1 and 3 months) were sacrificed. Sera were analyzed for acid (AcP), alkaline (AlkP), and tartrate‐resistant acid phosphatase (TRAP). Bone histomorphometry was done on parasagittal sections of maxillary molars. Molar drift was quantified cephalometrically. Results: Distal surfaces contained more osteoclasts and higher osteoclast percents than mesials at both ages (P<0.001). There were also more osteoclasts on the distals of the older rats as compared to the young (P<0.001). Osteoblast percents were higher (P<0.001) in the older rats on both surfaces. Mesials had higher doublelabeled surface, MAR and BFR than distals in the younger rats (P<0.001). The younger rats had higher (P<0.001) AlkP, AcP, and TRAP. There were no age‐specific differences in rat of molar drift. A model of rate of molar drift (P<0.0015) containing bone formation measures accounts for 54.9% of the variability. Conclusions: We conclude that the bone turnover dynamics adjacent to maxillary first molars represent predominantly remodeling on the distal in both groups and modeling on the mesial only in the young rats, that distal molar tooth drift reflects alveolar bone turnover, and that alveolar bone manifests the marked reduction in bone cell activity that occurs in the rat skeleton after 8 weeks but that this reduction is compensated by recruiment or maintenance of more bone cells at these sites. © 1995 Wiley‐Liss, Inc.
Ultrastructural and functional differentiation of hepatocytes under long‐term culture conditions
Authors: Knop Erich , Bader Augustinus , Böker Klaus , Pichlmayr Rudolf , Sewing Karl‐Friedrich 
Published: February 2005

AbstractBackground: Studies on hepatocytes grown in different culture systems have shown that these cells rapidly dedifferentiate on a single support with liquid medium on top (single gel technique). However, in systems sandwiching them between two layers of extracellular matrix (double gel technique), the cells are able to regain and maintain typical light microscopical appearance and function. Their ultrastructural morphology is as yet unknown.Methods: Isolated, adult rat hepatocytes were grown in both systems, and their fine structure (thin section electron microscopy) and the functional ability of albumin production (immunoassay) were studied and compared in both culture systems after 2,7, and 14 days.Results: The hepatocytes in conventional single gel culture did not completely regain their normal morphology and rapidly underwent progressive dedifferentiation. This was characterized by loss of cell polarization in terms of obliteration of the bile canaliculi‐like intercellular expansions, loss of cell membrane differentiations, and reduction of organelles. Cytoskeletal components gradually increased, building up large filamentous zones underneath the plasma membrane. In double get culture, the hepatocytes reachieved and maintained intact morphology and polarity over at least 14 days. The bile canaliculi were formed, preserved, or even enlarged and were associated with dense peribiliary bodies and Golgi fields. The plasma membrane facing both collagen layers bore numerous cytoplasmic microprojections like the sinusoidal surfaces of the hepatocytes in situ. Cell organelles, glycogen particles, and lipid droplets were always present.Conclusions The hepatocyte is a cell type in which ultrastructural and functional differentiation are strongly interdependent. For these cells, the morphological microenvironment (i.e. the bipolar position of the extracellular matrix) may be as improtant or even more decisive for maintenance of normal cell differentiation than modifications of the composition of the matrix itself or addition of other cell types, as focused in other studies. © 1995 Wiley‐Liss, Inc.