bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression patterns of ammonia‐metabolizing enzymes in the liver, mesonephros, and gut of human embryos and their possible implications
Authors: Dingemanse Maria A. , Lamers Wouter H.
Published: February 2005

Human and ungulate embryos can catabolize amino acids for energy production, whereas rodent embryos cannot, raising the question whether studies of rodent model systems are suitable for extrapolation to the human situation. Therefore, we investigated the expression of the amino acid‐ and ammonia‐metabolizing enzymes glutaminase, glutamate dehydrogenase, glutamine synthase, carbamoylphosphate synthase, and arginase immunohistochemically in a graded series of human embryos and fetuses. During human development the expression of these enzymes is first seen in the liver, then in the mesonephric kidney, and finally in the small intestine. Such a simultaneous expression of nitrogen‐metabolizing enzymes was not seen in any other organ. The early appearance of the enzymes involved in amino acid and ammonia metabolism in the human liver, compared to, for example, the rat liver, suggests that catabolism of amino acids may provide an important supply of metabolic energy for the human embryo. The coexpression of glutaminase, glutamate dehydrogenase, and carbamoylphosphate synthase, but not of arginase, in the mesonephros and the small intestine suggests that these organs are involved in the biosynthesis of intermediates of the ornithine cycle, e.g., arginine or citrulline. From a comparison of the developmental appearance of ornithine cycle enzymes in different mammalian species we postulate that an early appearance of these enzymes is generally associated with a relatively slow prenatal growth rate and the use of amino acids as metabolic fuel. © 1994 Wiley‐Liss, Inc.
Posterior right diagonal artery
Authors: Nerantzis Christos E. , Gribizi Joan E. , Margaris Nikos G. , Antonelis Jhon Pr. , Salahas Tassos I. , Koroxenidis Gabriel T.
Published: February 2005

Background: There is general confusion about a branch of the posterior segment of the right coronary artery that has been referred to as 1) the lower trunk of a divided right coronary artery; 2) a posterior reflection of the right marginal artery; 3) the ramus lateralis; and 4) a posterolateral branch or a posterior descending artery.

Materials: Three hundred human hearts were studied by direct observation, X‐ray films, and corrosion casting.

Results: This branch of the right coronary artery arises either after the right marginal artery (in 84% of hearts) or it constitutes the continuation of this artery in the remaining 16%. We named it the posterior right diagonal artery (PRDA). It was found in 14% of 266 hearts of right dominant type. It was present in 39% when the length of the posterior descending artery (PDA) was shorter than half of the length of the posterior interventricular sulcus (PIS) and in 6% when it was longer. When the PRDA originated directly from the RCA, the RMA appeared underdeveloped; the PRDA always occupied the inferior part of the PIS and appears either as continuation of a short PDA or as a replacement for a long PDA from the point where this artery leaves the PIS to enter the posterior wall of the left ventricle. The PDRA when present serves as a bridge between the RCA and the left anterior descending artery.

Conclusions: These findings are of practical importance for the correct interpretation of coronary arteriographies and in the field of coronary artery surgery. © 1994 Wiley‐Liss, Inc.
Cytochemical characterization of oligosaccharide side chains of the glycoproteins of rat zona pellucida: An ultrastructural study
Authors: Avilés Manuel , Martínez‐Menárguez José Angel , Castells María Teresa , Madrid Juan Francisco , Ballesta José
Published: February 2005

Background: The zona pellucida (ZP), an extracellular matrix which surrounds mammalian oocytes, is formed by different glycoproteins. Several studies have revealed that carbohydrate residues present in glycoproteins of ZP play a key role in the sperm‐egg recognition. However, the origin and the biochemical composition of ZP remain to be completely resolved.

Methods: ZP glycoproteins from rat ovarian follicles were investigated at light and electron microscopic level by the application of lectins conjugated to peroxidase, digoxigenin, and colloidal gold in combination with enzyme and chemical treatment. A quantitative analysis was also performed.

Results: ZP shows reactivity to WGA, DSA, LFA, AAA, RCA I, and MAA. SBA and PNA showed a variable reactivity ranging from negative to strongly positive. A uniform pattern of binding throughout ZP was observed with DSA, Con A, AAA, MAA, and LFA. However, labeling by RCA I and SBA was higher in the outer ZP while PNA and WGA showed a higher binding in the inner ZP. Lectin reactivity was detected in cortical granules, endoplasmic reticulum, Golgi apparatus, vesicles, and multivesicular bodies of oocytes.

Conclusions: ZP contained the terminal disaccharides Galβ1,4GlcNAc, Galβ1,3GalNAc, and GalNAcβ1,3Gal and the trisaccharides Neu5Acα2, 3Galβ1,4GlcNAc, Neu5Ac‐Galβ1,3GalNAc, and Neu5Ac‐GalNAcβ1,3Gal sequences. The occurrence of Fucose residues α 1,6 linked to the inner core region of N‐linked glycoproteins of ZP was demonstratd by the use of several fucose‐specific lectins. Methylation‐saponification treatment in combination with lectin cytochemistry reveals that Gal, GalNAc, and polyllactosamine residues of rat ZP glycoproteins contain sulphated groups. The reactivity observed in ooplasmic vesicles was similar to that of ZP, thus suggesting that the oocyte is the site of synthesis of ZP glycoproteins. © 1994 Wiley‐Liss, Inc.
Collagen fibrils in the odontoblast layer of the rat incisor by scanning electron microscopy using the maceration method
Authors: Tabata Shoji , Nakayama Tsuguhiro , Funakoshi Kimitake , Yasui Kinya , Wada Kaoru , Uemura Masanori
Published: February 2005

Background: There is not universal agreement on the existence of the extracellular pathway from the pulp along the odontoblast layer to the predentin.

Method: To confirm this pathway, the architecture of collagen fibrils in the rat incisor dentin and pulp, especially in the odontoblast layer of the lateral (periodontal ligament) sides of the tooth, was demonstrated in the present investigation using scanning electron microscopy of the maceration method for collagen networks.

Results: Numerous collagen bundles were observed in the odontoblast layer in the mature odontoblast region which, except for the young odontoblast region, comprises the major portion of the incisor. The collagen bundles went from the pulp, through the odontoblast layer, and were woven into the collagen network of the predentin. The meshwork structure was composed of fine secondary fibrils among these collagen bundles. The surface of the predentin contained many oval‐shaped holes which were surrounded by collagen fibrils. Fracturing the dentin longitudinally relative to the dentinal tubules revealed that the arrangement of the collagen fibrils at the surface of the tubules was either circular or oblique. In the young odontoblast region, i.e., the thin portion from the apical end of the incisor where the mineralization of the dentin does not occur and where the height of the odontoblasts was less than 30 μm, many thick bundles composed of thick collagen fibrils ran straight from the pulp to the predentin through the odontoblast layer and fanned out into the collagen network of the predentin. These thick bundles might correspond to the so‐called “von Korff fibers.” The distribution of collagen fibrils in the pulp was random except on the surface of the blood vessels where the fibrils comprised two sheets of collagen: the inner sheet which coursed longitudinally to the long axis of the vessel, and the outer sheet which ran transversely.

Conclusion: It was considered that the fluid in the pulp could flow to the predentin along the collagen fibrils through the tight junction between the odontoblasts. © 1994 Wiley‐Liss, Inc.
Endocrine tissue associated with the pancreatic ductal system: A light and electron microscopic study of the adult rat pancreas with special reference to a new endocrine arrangement
Authors: Bertelli Eugenio , Regoli Mari' , Bastianini Arnaldo
Published: February 2005

Background: A substantial part of the endocrine pancreas has been previously described as being located either close to the excretory ducts as small clusters of endocrine cells and as Islets of Langerhans, or associated with the ducts as single endocrine cells scattered through the ductal epithelium.

Methods: Four Wistar white adult rats were sacrificed and perfused via the thoracic aorta with 2.5% glutaraldehyde. After the usual treatment for the transmission electron microscopy, pieces of pancreas were sectioned consecutively for light microscopy. Consecutive ultrathin sections were performed in the most interesting cases.

Results: The observations previously reported were confirmed. In addition, a new endocrine arrangement was detected and described as buds of endocrine cells (mainly B‐cells) protruding from the ductal epithelium into the surrounding tissue.

Conclusions: The authors propose to explain the endocrine buds as components of the gastro‐entero‐pancreatic system or as a stage of an endocrine pancreatic “neo‐histogenesis” occurring in the adult rat pancreas. © 1994 Wiley‐Liss, Inc.
Morphological studies of hypomineralized enamel of rat pups on calcium‐deficient diet, and of its changes after return to normal diet
Authors: Bonucci Ermanno , Lozupone Enrico , Silvestrini Giuliana , Favia Angela , Mocetti Patrizia
Published: February 2005

Background: Micro‐hardness investigations have shown that rat pups nursed by mothers on a low calcium diet and weaned with the maternal calcium‐deficient diet develop hypomineralized enamel. The inorganic and organic components of this enamel, their relationships, and their changes after return to normal diet have been studied by light and electron microscopy.

Methods: The maturation zone of incisor enamel has been studied in: (1) rats nursed for 20 days by mothers on a low calcium diet and weaned for 30 days with the same diet (E1 enamel); (2) rats that after the calcium‐deficient diet were fed normal diet for 10 days (E2 enamel); and (3) rats nursed for 20 days by mothers on a normal diet and weaned for 30 days with a normal diet (controls).

Results: The results showed that E1 enamel was hypomineralized, as noted by its Azure II‐Methylene blue stainability in undecalcified sections, its light staining with the von Kossa method, and its ultrastructure. E1 crystallites, although present throughout the whole enamel, were thinner than those of E2 enamel, which were similar to those of controls. E1 interrod crystallites were thicker in the intermediate than in the dentinal zone and were thicker than rod crystallites. Organic matrix was present throughout the whole E1 enamel. Its organic components (crystal ghosts) had the same shape, arrangement, and organization as those of inorganic crystallites. Crystal ghosts were greatly reduced in E2 enamel and in controls.

Conclusions: The results lead to the conclusions that: (1) E1 enamel is hypomineralized, and its degree of calcification is restored by return to a normal calcium diet; (2) intra‐ and interprismatic calcification occurs in a different way; (3) crystallite thickness is initially greater in dentinal than in the superficial zone and is reversed as crystallite growth is completed; and (4) loss of enamel proteins is necessary for completion of crystallite growth and not for crystallite formation. © 1994 Wiley‐Liss, Inc.
Appearance of complex branched fibers following repetitive muscle trauma in normal rat skeletal muscle
Authors: Tamaki Tetsuro , Akatsuka Akira
Published: February 2005

Background: 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

Background: 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

Through 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Galectin‐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

Background: 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

Background: 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.
Morphology of the left atrial appendage
Authors: Ernst Günther , Stöllberger Claudia , Abzieher Friedrich , Veit‐Dirscherl Walter , Bonner Elisabeth , Bibus Brigitte , Schneider Barbara , Slany Jörg
Published: February 2005

Background: When examining the left atrial appendage by transesophageal echocardiography, differences in size and shape of the left atrial appendage are to be observed. The study was carried out with the aim of investigating the morphology of the left atrial appendage and to find associations with pathologic cardiac findings.

Methods and results: In 220 cases (106 female, 114 male, mean age 72 ± 13 years) a cast of the left atrial appendage was made after the post mortem examination by using synthetic resin. In 198 cases an ECG was available (sinus rhythm n = 143, atrial fibrillation n = 55). The casts were described in respect to course and ramifications of the principal axis. The casts were measured concerning orifice diameters, outline, and volume. Most frequently (42%) the course of the principal axis was angulated below 100°. More than five ramifications of the principal axis were found in 56% of the casts. The volume ranged from 770–19,270 mm3 (mean 5,220 ± 3,041). When comparing the clinical and autopsy‐data of the patients with the morphology of the casts, associations could be found between the volume of the casts and atrial fibrillation (7,060 mm3 as compared to 4,645 mm3 in sinus rhythm, P < 0.01), left ventricular hypertrophy (5,740 mm3 as compared to 4,639 mm3 without hypertrophy, P < 0.01), myocardial scars (5,923 mm3 as compared to 4,891 mm3 without scars, P < 0.05), closed foramen ovale (5,515 mm3 as compared to 4,037 mm3 with patent foramen ovale, P < 0.01), and left atrial appendage thrombi (8,566 mm3 as compared to 5,027 mm3 without thrombi, P < 0.01).

Conclusion: Left atrial appendages are formations greatly varying in volume and shape. This variability should be considered when interpreting images of the left atrial appendage, and in particular when diagnosing thrombi. © 1995 Wiley‐Liss, Inc.
Pericyte‐endothelial gap junctions in developing rat cerebral capillaries: A fine structural study
Authors: Fujimoto Katsukuni
Published: February 2005

Background: Fine structural study revealed the intercellular coupling between the pericyte and the endothelial cells via the gap junctions, in the capillaries of the basal forebrain of rat embryos.

Results: Gap junctions were constructed by the adluminal plasmalemma of pericyte and the abluminal plasmalemma of endothelial cells.

Conclusions: Gap junctions are membranous channels that directly join the cytoplasms of the pericyte and endothelial cell and imply some substantial role for the pericyte on the endothelial proliferation. It is postulated that the function of the pericyte in the prenatal mammals are assigned to the regulation of the development of cerebral microcirculation. © 1995 Wiley‐Liss, Inc.
Three‐dimensional (3D‐) reconstruction of M cells in rabbit peyer's patches: Definition of the intraepithelial compartment of the follicle‐associated epithelium
Authors: Regoli Marì , Bertelli Eugenio , Borghesi Chiara , Nicoletti Claudio
Published: February 2005

One of the major cell components of the rabbit follicle‐associated epithelium is represented by the M cells. M cells are able to harbour variable amounts of immunocompetent cells inside peculiar invaginations of their basolateral cytoplasmic membrane, currently referred to as “pockets.” This study provides a description of the exact spatial relationships between the M cells and the cells harboured in these so‐called “pockets.”

Pieces of Peyer's patches, taken from the small intestine of an adult male rabbit, were treated as usual for conventional electron microscopy. Consecutive semithin and ultrathin sections were made through the entire thickness of the follicle‐associated epithelium along planes parallel to the mucosal surface. Micrographs, taken from the ultrathin sections, were transposed into a software MacDraw Pro to obtain a computerized three‐dimensional reconstruction.

Three‐dimensional reconstruction of the M cells showed that the “pockets” were not formed by mere invaginations of the cytoplasmic membrane, but that they resulted from the branching of the supranuclear portion of the M cell cytoplasm around the M cell‐infiltrating lymphocytes. These intrusive cells could be found inside the “pockets” or lined up with one another, in vertical columns, bordering on the basal aspect of the M cells. The particular arrangement of the M cell apical cytoplasm created a labyrinth within the follicle‐associated epithelium, which could be assumed as a real intraepithelial compartment expandable virtually throughout all the epithelium.

The functional meaning of the intraepithelial compartment delimited by the M cells and its possible role is discussed. In particular, the definition of a new intraepithelial compartment of the follicle‐associated epithelium, in order to differentiate it from the more generic intraepithelial compartment of the intestinal epithelium, is proposed. © 1995 Wiley‐Liss, Inc.
Immunocytochemical localization of the protein reactive to human β‐1, 4‐galactosyltransferase antibodies during chick embryonic skin differentiaion
Authors: Akimoto Yoshihiro , Obinata Akiko , Endo Hiroyoshi , Furukawa Kiyoshi , Aoki Daisuke , Nozawa Shiro , Hirano Hiroshi
Published: February 2005

Background: β‐1, 4‐Galactosyltransferase (GalTase) transfers galactose from UDP‐galactose to terminal N‐acetylglucosamine in glycoconjugates and is located both in the Golgi apparatus and in the plasma membrane. The cell surface GalTase is thought to be involved in cell‐to‐cell recognition and cell‐to‐extracellular matrix interaction.

Methods: By the use of specific monoclonal antibodies against human GalTase, changes in cell surface localization of the protein reactive to the antibodies in chick embryonic skin during its differentiation in vivo and in vitro were detected immunohistochemically at both light‐ and electron microscopic levels. The distribution of glycoconjugates having terminal N‐acetylglucosamine residues was detected by staining with succinylated wheat germ agglutinin (s‐WGA).

Results: Under the light microscope, intense immunostaining was observed in the keratinized epidermis, particularly in the intermediate layer. Marked changes in the localization of the staining were observed in vitamin A‐induced mucus‐secreting skin, in which keratinization was suppressed. The localization of the immunostaining was in parallel with that of glycoconjugates having terminal N‐acetylglucosamine residues.

Immunoelectron microscopically the immunostaining was located on the cell surface and in the intercellular space of the desmosomes in the intermediate cells of the keratinized epidermis. However, the staining was not present on the cell surface but was detected on the limiting membrane of the mucous granules, in the mucous metaplastic epidermis. In contrast, the staining was always found in the Golgi apparatus in all of the cells.

Conclusions: These results suggest that the protein reactive to human GalTase antibody may be involved in chick epidermal differentiation. © 1995 Wiley‐Liss, Inc.
Age‐induced hypertrophy of astrocytes in rat supraoptic nucleus: A cytological, morphometric, and immunocytochemical study
Authors: Berciano Maria Teresa , Andres Maria Auxiliadora , Calle Ester , Lafarga Miguel
Published: February 2005

Background: In the adult rat, neuron‐astroglia interactions in the supraoptic nucleus (SON) are characterized by the structural and functional plasticity of astrocytes in response to several physiological and experimental conditions. This study has analyzed the plasticity of the supraoptic nucleus astrocytes in response to the age‐induced changes in neuronal activity.

Methods: The study was performed in 5‐, 12‐, 18‐ and 24‐month‐old rats. The cytology and organization of astrocytes in the SON were examined using glial fibrillary acidic and vimentin immunocytochemistry and ultrastructural and morphometric analysis.

Results: No significant age‐related variations in the total number of neurons and astrocytes in the SON were detected, although a few degenerating neurons were found in old rats. An age‐dependent increase in GFAP immunoreactivity was observed at the ventral glial lamina, perivascularly and between neuronal perikarya. Vimentin overexpression was also detected in ventral lamina astrocytes with advancing age. At the cell nucleus level, we observed an age‐associated increase in nuclear size and in the number of coiled bodies, nuclear bodies, and “cleared” nucleoplasmic areas, as well as changes in the nucleolar organization. At the cytoplasmic level, characteristic ultrastructural features in astrocytes of old rats were the hypertrophy of intermediate filament bundles and the formation of an extensive network of Golgi stacks interlinked by tubulovesicular elements. Glial filaments were often associated with the nuclear envelope and polyribosomes.

Conclusions: The increased GFAP and vimentin immunoreactivity and the morphometric and cytological changes in rat SON astrocytes may reflect a sustained upregulation of cellular activity with age, resulting in hypertrophy of glial perikarya and cell processes. Several factors that are known to influence the expression of the astrocytic phenotype, such as signals produced by degenerating neurons and activated microglia, as well as variations in neuronal activity are considered possible causes of the age‐associated changes in SON astrocytes. © 1995 Wiley‐Liss, Inc.
Immunolocalization of N‐CAM in the heart of the early developing rat embryo
Authors: Okagawa Hiroto , Nakagawa Masao , Simada Morimi
Published: February 2005

Background: Neural cell adhesion molecule (N‐CAM) is important in the migration of neural crest cells and is expressed in the developing heart. The pattern of expression of N‐CAM in the heart of early rat embryos was investigated to shed light on the potential role of N‐CAM in cardiac neural crest cell migration.

Methods: N‐CAM expression was studied by immunohistochemistry in Sprague‐Dawley rat hearts between embryonic days 11.5 and 15.5 HNK‐1 immunoreactivity was also investigated for comparison with that of N‐CAM.

Results: A continuity of N‐CAM immunoreactivity was transiently detected from the outflow tract to the recurrent nerve. N‐CAM was also expressed around the sinus venosus, inferior vena cava, sinotrial septum, and coronary sinus, as well as on mesenchymal cells in the atrioventricular endocardial cushion tissues.

Conclusions: The continuous N‐CAM immunoreactivity from the outflow tract to the recurrent nerve appeared to represent the pathway along which cardiac neural crest cells migrate. N‐CAM‐immunoreactive sites around the sinus venosus may correspond to migrating neural crest cells that differentiate into nerve fibers or cardiac ganglia. Results indicate that N‐CAM may play an important role in the migration, proliferation, and transformation of neural crest cells, thereby contributing to cardiac morphogenesis and to innervation around the heart and great arteries. © 1995 Wiley‐Liss, Inc.
Ultrastructural changes of secretory cells of salamander lingual salivary glands under varying conditions
Authors: Kurabuchi Shingo , Nakada Hiroyuki , Aiyama Shigeo
Published: February 2005

Background: In general the ultrastructure of secretory cells can be modified under secretory stimulated and non‐stimulated conditions. The ultrastructure of the lingual salivary glands of hibernating salamanders in the natural environment was examined and compared to those of fasted and fed animals kept in the laboratory.

Methods: Hibernating salamanders of the species Hynobius tokyoensis were collected from the natural environment during the winter breeding season and sacrificed for this study. One group was sacrificed immediately, another group was kept under fasted condition, and another group was regularly fed; both of the latter groups were kept at room temperature for 1 month and then sacrificed. The tongue was fixed for electron microscopy and processed by conventional methods, and semithin sections were histochemically examined for glycoconjugates.

Results: The lingual salivary glands of this salamander species were composed of simple or often branched tubular glands opening onto the dorsal surface of the tongue. The secretory cells which composed their terminal portions were all columnar in morphology and histochemically mucous in nature. Under hibernation or prolonged fasting at room temperature, the mucous granules of these columnar secretory cells were decreased in number and the Golgi apparatus appeared inactive. A conspicuous structural peculiarity was multiple fingerprint‐like structures of the rough‐surfaced endoplasmic reticulum (RER). Most of these membranes were composed of stacks of tightly packed cisternae. Under regular feeding, the mucous granules were closely packed in the cytoplasm of the secretory cells and the basal necleus was slightly enlarged. The Golgi apparatus showed progressive activation with distended saccules. The unique membranous arrangement of the RER which was observed in the fasting animals was completely absent, and the cisternae were irregular in width with considerable variation of the intercisternal spaces.

Conclusions: The tongue of the salamander H. tokyoensis has numerous tubular salivary glands which are mucous in nature. The architecture of the organelles in the secretory cells is subject to modification in response to the cellular metabolism. © 1995 Wiley‐Liss, Inc.