bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonin-lmmunoreactive Terminals in the Mesencephalic Trigeminal Nucleus of the Rat: An Electron Microscopic Immunocytochemical Study
Authors: Liem R.S.B. , Copray J.C.V.M. , van Willigen J.D.
Published: July 2008

The morphological characteristics and distribution of serotonin-immunoreactive terminals within the rat mesencephalic trigeminal nucleus (Me5) were studied using immunocytochemical electron microscopy. Fibers, immunostained by specific antibodies raised against serotonin, were distributed throughout the entire rostrocaudal portion of the Me5. Examination of 355 serotonergic terminals in the caudal part of the Me5 revealed that 93% formed synaptic contacts with dendritic shafts: 68% on small (<1.5 μm diameter) and 25% on large (>1.5 μm diameter) dendrites. The remaining 7% formed axosomatic synapses, about a third of which are in contact with small spinous processes (somatic spines). Serotonin was also present in vesicle-filled boutons lacking synaptic-membrane specializations. Our data indicate that of all the dendritic synaptic and nonsynaptic inputs observed in the Me5 nucleus, the serotonergic component amounted to between 15 and 27%. More than half (58%) of the somatic synaptic input on the Me5 cells appears to be serotonergic. This suggests that, of all the somatic synaptic input on the proprioceptive primary sensory neurons of the Me5, the serotonergic afferent input probably has the most significance for the functioning of Me5 neurons.
A Reassessment of Goodrich’s Model of Cranial Nerve Phylogeny
Authors: Northcutt Glenn
Published: July 2008

The first detailed comparisons of the organization and development of craniate head structure occurred during the period 1870–1940. Most workers concluded that craniate heads were segmented, but there was no consensus regarding the nature or number of units forming head segmentation. Although a number of views are reflected in the literature, Goodrich’s model has dominated subsequent discussions. Goodrich’s model assumes that the head of the earliest gnathostomes consisted of 8 segments, and that each head segment, except for the premandibular segment, consisted of epimeric and hypomeric muscle, which was innervated by homologues of ventral and dorsal spinal nerves, respectively. Goodrich’s model thus assumes that there is a simple one-to-one relationship between nerves and mesodermal derivatives. Review of current data on the roles of neural crest, neuromeric, placodal and somitomeric tissue in the development of vertebrate heads refutes Goodrich’s contentions and suggests that at least three, possibly four, separate series of cranial nerves exist in vertebrates and that these nerve series are related to each of the iterative developmental tissues of the head in a different manner.
Conservation of Neuroepithelial and Mesodermal Segments in the Embryonic Vertebrate Head
Authors: Gilland E. , Baker R.
Published: July 2008

The organization of embryonic efferent cranial nerves is addressed here by inter-species comparison of segmentally patterned neuromeres, efferent neuronal populations and early mesodermal sources of target muscles. The segmental constancy of these three structural patterns is evaluated for elasmobranch teleost, reptile, bird and mammal embryos and compared with the segmentally restricted expression patterns of Hox genes. A conserved series of hindbrain neuroepithelial segments (rhombomeres) is present in all of these taxa. Dye-labeling experiments demonstrate that the segmental locations of efferent neurons projecting through individual cranial nerves are likewise highly conserved. Notable segmental variation is however shown in the location of the VI and IX–XII motoneurons, suggesting the likelihood of homeotic-like changes in relations between rhombomere and neuronal ‘identity’ during vertebrate evolution. Since experimentally induced shifts in expression borders of Hox genes appear to be correlated with alterations in segment identity and/or neuronal phenotype, the need for further examination of segmental locations of specific neuronal groups and the segmental expression patterns of Hox genes between species is emphasized. Comparison of early cranial mesodermal subdivisions in elasmobranchs with descriptions of somitomeres in amniotes suggests that a series of axially unique mesodermal populations may also be conserved throughout vertebrates. The possibility is raised that common mechanisms of axial specification may underlie the initial appearance of segmental patterning in both neural and mesodermal layers during gastrulation. Implications of these conserved patterns for understanding the phylogenetic origin of the vertebrate head are briefly discussed.
Cell Contacts in Early Human Pituitary Development
Authors: Stefanović V. , Babić Saraga , Wartiovaara J.
Published: July 2008

The ultrastructure of cell and tissue contacts in the developing human pituitary gland were studied in embryos from 3 to 5 weeks of age. At the early stage, the pituitary anlage, Rathke’s pouch (RP) of the pharyngeal gut wall, had no direct contact with the diencephalon. At later stages, several close cell-to-cell contact sites were observed between the two tissues, on the upper anterior aspect of RP. However, even at these contact sites a thin layer of extracellular material always remained between the tissues, elsewhere covered by a well-developed basement membrane. RP was, in addition, surrounded by close-coming mesenchymal cells during the time studied. The findings are discussed in reference to different tissue interaction models.
Expression of Casein Kinase 2 during Mouse Embryogenesis
Authors: Mestres P. , Boldyreff B. , Ebensperger C. , Hameister H. , Issinger O.-G.
Published: July 2008

This paper deals with the expression and distribution of casein kinase 2 (CK-2) subunits in mouse embryos at different developmental stages. Expression was investigated at the mRNA level of CK-2 α- and β-subunits by in situ hybridization and distribution at the protein level by immunohistochemistry using CK-2-α and CK-2-β-specific antibodies, respectively. In general both methods gave similar results. In earlier stages of mouse embryonic development (day 10.5 after coitus) CK-2 was more expressed in neuroepithelia than in all other tissues. From day 11.5 after coitus on, high expression of CK-2 was detected in all epithelia. From day 16.5 on, all tissues and anlagen of the fetus involved in organogenesis revealed a higher CK-2 expression as compared with secondary mesenchyma. The only difference between in situ hybridization and immunocytochemistry was observed in the skin. Transcripts of CK-2 were found mostly in the basal layer of the epidermis and in the nuclei of keratinocytes, whereas CK-2 protein was almost exclusively found in the cytoplasm of epidermal cells.
Identification of Somatomammotroph Cells in Lactating Goats (Capra hircus) by Fluorescence and Immunogold Techniques
Authors: Sánchez J. , Navarro J.A. , Bernabé A. , Gómez S. , Garcés B. , Gómez M.A.
Published: July 2008

The occurrence and ultrastructural morphology of somatomammotroph cells, in the anterior pituitary tissue of the goat, is studied using fluorescence microscopic double staining and two methods of double immunogold staining combined with electron microscopy. Under the fluorescence microscope numerous monohormonal cells, either mammotroph cells (prolactin, PRL, cells) or somatotroph cells (growth hormone, GH, cells) are observed, but cells containing both hormones (somatomammotroph or SMT cells) are scarce. SMT cells do not differ ultra-structurally from monohormonal cells, and the cytoplasm contains two populations of granules, each reactive only for one of the antisera, either antisheep GH or antisheep PRL.
Morphology and Analysis of the Development of the Human Temporomandibular Joint and Masticatory Muscle
Authors: Sato I. , lshikawa H. , Shimada K. , Ezure H. , Sato T.
Published: July 2008

The calcification levels of the mandible and the temporal bone of human fetuses, which ranged from 12 to 32 weeks of gestation, were systematically investigated with a soft X-ray analyzer linked to an image analyzer. The profile of the condylar process (head) revealed high levels of calcification, in contrast to that in the mandibular fossa of the temporal bone. The basal portion of the condylar process and the mandibular notch exhibited moderate calcification from 12 weeks of gestation. The weight and the cross-sectional areas of the muscle and the muscle fibers in masticatory muscles (masseter, temporal, medial, and lateral pterygoid muscles) are all increased gradually during development from 12 to 32 weeks of gestation. These changes in calcification and in cross-sectional area of muscle suggest that muscle development may be related to bone calcification during formation of the mandible.
Ultrastructural Changes of Epidermal Langerhans Cells in Pregnant Guinea Pigs
Authors: Alp H. , Durgun B. , Müftüoğlu S. , Inan S. , Aşan E.
Published: July 2008

An association between pregnancy and a depression in cellular immunity has long been known, but the reason for this is far from clear. To investigate the possible role of Langerhans cells (LC) in immunosuppression during pregnancy, we examined the epidermal LC morphology of pregnant guinea pigs ultrastructurally. An altered morphology of epidermal LCs was observed in all specimens obtained from pregnant guinea pigs. LCs were found to be activated in pregnancy.
Nerve Supply to the Accessory Soleus Muscle
Authors: Sekiya S. , Kumaki K. , Yamada T.K. , Horiguchi M.
Published: July 2008

An accessory soleus muscle was found in the right leg of a cadaver in the dissecting room. This anomalous muscle was situated medially between the distal part of the tibia and the tendo calcaneus. The muscle arose from the anterior aponeurosis of the soleus muscle and was attached with a separate tendon to the calcaneus anteromedial to the tendo calcaneus. The soleus muscle was supplied by two nerves from the tibial nerve. The ramus posterior entered its posterior surface near the proximal border, and the ramus anterior entered the bipenniform part which was located on the anterior aspect of the soleus. One of branches from the r. anterior descended on the surface of the medial half of the bipenniform part and gave off a few twigs for this muscle part. Finally, its terminal entered the accessory soleus muscle and ramified in this muscle. In a teased preparation of the tibial nerve, both the nerve fibres composing this branch to the anomalous muscle and those constituting the r. anterior proper which supplied the bipenniform part were contained in the same funiculus. This mode of nerve supply to the soleus and the accessory soleus muscle suggested that this anomalous muscle derived from the part of the proper soleus muscle supplied by the r. anterior.
In vitro Response of Articular Cartilage from Mature Mice to Human Transforming Growth Factor Beta
Authors: Livne E.
Published: July 2008

The ability of human transforming growth factor-β1 (hTGF-β1) to induce proliferation and matrix synthesis in articular cartilage of aging mice was studied using an organ culture system of mandibular condylar cartilage. An increased incorporation of Η-thymidine into DNA and of 35S-SO4 into sulfated glycosaminoglycans was observed in cultures supplemented with 1–10 ng/ml TGF-β and with 1 % fetal calf serum. In these cultures numerous clusters of chondrocytes containing a well-developed rough endoplasmic reticulum were seen. Articular cartilage from mature animals often develops osteoarthritic degenerative lesions, thus the induction of cell proliferation and of matrix synthesis may be an indication of a tissue repair process in cartilage from maturing animals.
Antigen Stimulation Alters the Expression of S-100 Protein in the Giant Macrophages and Follicular Dendritic Cells of the Guinea Pig Lymph Nodes
Authors: Atoji Y. , Nakaoka T. , Yamamoto Y. , Suzuki Y.
Published: July 2008

Injections of chick erythrocytes were employed to examine the relationship between expression of S-100 protein and antigen stimulation in the giant macrophages (GM) and follicular dendritic cells (FDC) of guinea pig lymph nodes by an immunocytochemical method. Popliteal lymph nodes were observed 1, 3, 6 and 12 h, then 1, 2 and 3 days, and finally 1, 2 and 4 weeks after injection of chick erythrocytes into hind foot pads. All GM in control lymph nodes were dendritic in shape at the cortical surface and strongly immunoreactive to S-100 protein. In lymph nodes of injected animals, three types of GM were observed at the cortical surface: cells were S-100-protein-positive/phagocytosis-positive, S-100-protein-positive/phagocytosis-negativeandS-100-protein-negative/phago-cytosis-positive. GM that were S-100-protein-negative/phagocytosis-positive appeared from 1 h onwards, reaching a maximum number at 6 h and then decreasing in number with time at the cortical surface. In the medulla, such cells were observed after 1 h, increasing to a maximal level at 6 h and, thereafter, gradually decreasing in number. These results indicate that expression of S-100 protein in GM is altered by antigen stimulation and that GM move in the lymph nodes. The same pattern of expression of S-100 protein was demonstrated in the FDC 1 week after injection.
Coexistence of Vasoactive Intestinal Polypeptide and Neuropeptide Y Immunoreactivity within Axon Terminals in the Canine and Human Lower Esophageal Sphincter: Electron Microscopy by a Double Immunogold Labeling Procedure
Authors: Tsumori T. , Ando A. , Domoto T. , Oki M. , Nakamura T.
Published: July 2008

Subcellular localization of vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) immunoreactivity within nerves was investigated in the lower esophageal sphincter of dogs and humans by double immunogold staining of sections prepared for electron microscopy. Coexistence of VIP and NPY immunoreactivity was clearly demonstrated in the large granular vesicles (LGVs) in axon terminals that were closely associated with the smooth muscle cells, as well as in the LGVs within the perikarya of neurons located in the myenteric plexus. Some LGVs appeared immunopositive only for VIP or NPY. This phenomenon might have been partly due to the fact that the double-labeling procedure with immunogold particles of different sizes was performed on both faces of each section. The results obtained in this study suggest that VIP and NPY are synthesized in the same neuron, stored in the same axon terminal, and released together to act on sphincter muscle cells.
Development of Granule Cells, and Afferent and Efferent Connections of the Dentate Gyrus after Experimentally Induced Reorganization of the Supra- and Infrapyramidal Blades
Authors: Hartmann D. , Frotscher M. , Sievers J.
Published: July 2008

We have analyzed the development of the major afferent and efferent connections of the hamster dentate gyrus as well as the morphology of its granule cells, subsequent to a novel developmental defect. Following the selective destruction of the overlying meningeal cells by the neonatal administration of 6-hydroxydopamine, the majority of the glial and neuronal precursor cells destined for the infrapyramidal blade of the dentate gyrus are redirected into the suprapyramidal stratum granulosum, that subsequently becomes elongated and thickened. The remaining cells form a rudimentary infrapyramidal blade with a temporal delay of at least one week, the molecular layer of which is reduced in comparison to controls. This rudiment is either attached to the suprapyramidal blade by an apparently normal crest region or develops as a separate structure. Consecutive to this manipulation, the terminal field of the early-differentiating commissural and associational fibers expands in the suprapyramidal blade, whereas it is reduced in the late-forming infrapyramidal rudiment, the vacant space at the granule cell dendrites being taken over by entorhinal afferents. The efferent mossy fiber bundle does not show any differences along its course into the CA3 region, whereas hilar mossy fibers expand their intragranular distribution, sometimes contacting, but never invading the molecular zone. The morphology of the majority of the granule cells is entirely normal, however, a small but significant proportion maintains additional basal dendrites normally present only in immature, but not in adult rodents.
Developmental Characteristics of Trisomy 19 Mice
Authors: Lorke D.E.
Published: July 2008

Trisomy 19 (Tsl9), the only murine trisomy compatible with survival beyond birth, allows systematic studies on the effect of an additional chromosome upon postnatal development. In this review, developmental consequences of murine Tsl9 are presented. In Tsl9 mice, viability is limited to a few weeks postpartum. Body weight is markedly reduced. The occurrence of malformations of the cardiovascular, skeletal and central nervous systems depends on the parental genetic background. In all organ systems examined, development is delayed by 1-2 days. Tsl9 hematopoietic cells exhibit the same survival rate in lethally irradiated hosts as controls. In the CNS, morphological and morphometric studies fail to detect cytoarchitectonic abnormalities: the orderly pattern of development is not disturbed in the visual cortex, cerebellum, locus coeruleus (LC), optic nerve and retina; but neurogenesis, gliogenesis, myelination and invasion of blood vessels are each delayed by 1-2 days. In addition, size and cell number of different brain regions are reduced to a variable degree: the telencephalon and the cerebellar vermis are markedly hypoplastic, whereas the LC, the optic nerve and the retina are hardly reduced in size. Choline acetyltransferase activity is selectively reduced in the Tsl9 telencephalon, whereas the activity of the marker enzyme of the GABAergic system is decreased in all brain regions examined. In behavioral tests, visual capacities and orientation ability of Tsl9 mice develop with a 2-day delay, while motor coordination is more severely retarded; there is no response to auditory stimulation. Fetal Tsl9 ovaries show excessive oocyte degeneration. Development of the testes is only disturbed postnatally: differentiation of gonocytes to A spermatogonia and formation of B spermatogonia are severely disrupted, resulting in a striking reduction in germ cell number and a predominance of Sertoli cells. Histopathological changes exhibit marked intra-and interindividual variations. In addition, growth and lumen formation are impaired in the seminiferous tubules. The proliferative capacity of cultured Tsl9 cells is not altered. The activities of glutamate oxaloacetate transaminase-1 and phosphoglycerate mutase-1 are increased by 50%, compatible with a gene dosage effect of these two enzymes. Ganglioside composition is altered in the Tsl9 liver, but not in the brain, spleen and heart. Two-dimensional protein patterns show both chromosome-specific and chromosome-nonspecific changes, their frequency being far lower than expected from the number of proteins coded on chromosome 19. Possible pathogenetic mechanisms are discussed.
The Tunica media of the Thoracic Duct Contains a Heterogeneous Population of Muscle Cells
Authors: Bannykh S. , Bannykh G. , Mironov A.
Published: July 2008

The three-dimensional cyto-architecture and ultrastructure of cells composing the different regions of the tunica media of canine and feline thoracic ducts (ThD) were investigated by scanning and transmission electron microscopy. The tunica media of the intervalvular regions consists of 2-4 layers of circularly oriented ribbon-like smooth muscle cells (SMCs) of the contractile phenotype. Spot-like membrane contacts similar to gap junctions were observed between SMCs. In the parietal part of the valve’s sinus (PPVS), modified SMCs containing large lipid droplets were found. Occasionally, in the upper thoracic part of the ThD in the PPVS, we observed cardiomyocyte-like cells (CMLCs) arranged as circularly oriented bundles. Frequent interdigitation contacts were formed between SMCs and CMLCs, suggesting a possible involvement of the latter cell type in pacemaker activity of the ThD.
Morphogenesis of the Osteo-Architecture in the Carnassial Region of the Feline Mandible, as Demonstrated by Microfocal Radiography
Authors: Flachsbarth M.F. , Bartels T. , Meyer W. , Schwarz R. , Boos A.
Published: July 2008

For the first time, osteogenesis was observed using direct magnifying microradiography, a noninvasive technique that has a high power of resolution. Thus, it was possible to correlate different stages of bone maturation in the feline mandible with specific functional demands. Our observations suggest a relationship between osseous structure and the mode of feeding and content of the diet.
Superficial Branch of the Radial Nerve Emerging between Two Slips of a Split Brachioradialis Muscle Tendon: A Variation of Possible Clinical Relevance
Authors: Turkof E. , Puig S. , Choi M.S.S. , Schilhan R. , Millesi H. , Firbas W.
Published: July 2008

One hundred and fifty upper extremities of 75 nonrandomized human cadavers were dissected to study the topographical relationship between the brachioradialis muscle tendon (BRMT) and the superficial branch of the radial nerve (SBRN). A split BRMT was found in nine arms, while in five of those nine arms the SBRN emerged from under the brachioradialis muscle between the two slips of a divided BRMT to become superficial. This topographical relationship is mentioned sparsely in very old literature, yet its frequency has not been studied before. Further clinical investigations should be undertaken to study the clinical relevance of the above-mentioned topographical relationship.
Neurotrophy and Regeneration in vivo
Authors: Blottner D. , Baumgarten H.G.
Published: July 2008

Neural regeneration is a multistep event which appears to be controlled by neurotrophic factors such as neurotrophins and/or neurotrophic cytokines. Following traumatic, age- and/or disease-related responses, these molecules may be expressed and/or released by innervated target cells, neuron-ensheathing glial cells, recruited macrophages or by the neural somata themselves which altogether provide possible cues for neurotrophic strategies in vivo. In this respect, neurotrophic molecules may follow either paracrine, autocrine or even intracrine pathways in order to attenuate or even prevent neuronal degeneration. As neurotrophic molecules may have important functions as putative therapeutic agents for patients suffering from CNS disorders or from peripheral neuropathies, adequate and reliable animal lesion paradigms are of importance as in vivo assay systems. Axotomy models or selective neurotoxin-lesion models of anatomically well-defined neuron target connections are a first step towards assaying of neurotrophic actions in vivo. In lesioned central neural pathways, the existence of multineuronal networks, diffuse nuclear topography and a high degree of collateralization should be considered when studying regenerative potentials of trophic factors. Because of their simple organization and accessibility, peripheral neural pathways are particularly appealing as assay systems. As neurotrophic requirements and vulnerability vary among neural subsystems, in vivo lesion paradigms reveal pharmacological rather than physiological effects which have to be elucidated by more sophisticated experimental paradigms and molecular tools.
Invasiveness of Mouse Trophoblastic Cells in Connective Tissue
Authors: Bevilacqua E. , Abrahamsohn P.A.
Published: July 2008

Ectoplacental cones from 8-day-old mouse embryos were grafted into the dorsal subcutaneous tissue of host mice. The grafts were collected between the 3rd and 8th days after transfer and processed for morphological analysis by light and electron microscopy. Approximately 60% of the grafts formed hemorrhagic nodules in which only invasive, giant trophoblastic cells developed. These cells shared many morphological features with the trophoblastic cells involved in normal implantation. At the periphery of the nodules, trophoblastic giant cells were frequently seen growing toward the host connective tissue. The association between the trophoblast and fibrilar components of the extracellular matrix was examined. No direct association with collagen fibrils was noted; however, many areas of the surface of invasive cells were in close proximity with microfibrils of the extracellular matrix. Since only the invasive trophoblast cells exhibited such an association, a direct comparison was made with the process of trophoblast migration within the connective tissue.
Scanning Electron Microscopy of Collagen Fiber Orientation in the Bone Lamellar System in Non-Decalcified Human Samples
Authors: Pannarale L. , Braidotti P. , d’Alba L. , Gaudio E.
Published: July 2008

Previous studies on collagen fiber orientation have led to different interpretationsand theories about the fiber arrangement in the lamellar compact bone. The purpose of this investigation was to provide new and more in-depth data on fiberarrangement in the lamellar bone system in order to explain the orientation of thefiber bundles. This was carried out by applying a simple method of preparationwhich permitted observation of non-decalcified samples. A previously isolatedHaversian system was subjected to slow bending up to reaching the fracturepoint. Hence, the fracture surface was observed by SEM. The same sampleswere also observed by polarized light microscopy. A significant alternation offiber orientation in the adjacent lamellae was observed. Different domains of differently oriented fibers were present within the same lamella; conjugating fibersconnecting adjacent lamellae were also shown. This method avoided most of theartifacts due to chemical treatment of bone samples. The results can be easilyinterpreted by means of the same criteria applied in mechanics for the studyingof composite materials.
Paneth Cells of African Giant Rats (Cricetomys gambianus)
Authors: Satoh Y. , Ono K. , Moutairou K.
Published: July 2008

The ultrastructure of Paneth cells of African giant rats (Cricetomys gambianus), which were captured on the savanna in western Africa, was studied. The Paneth cells of Cricetomys were clustered at the bottom of crypts of the small intestine, but not of the colon. In the normal state, Paneth cells had a few secretory granules showing high electron density. Small clear vesicles which are a characteristic in laboratory albino rats were not conspicuous. Vacuolated Paneth cells and secreted materials from the Paneth cells were frequently found. This suggests that the secretion of Paneth cells of Cricetomys is active in the natural state. No phagocytotic figures were observed. After atropine sulfate treatment, secretory granules increased in size and number, whereas the electron density decreased, similar to that of goblet cell granules. However, the granules were not stained by alcian blue or by PAS. Inhibition of secretory stimuli by atropine can alter the intracellular processing of secretory substances in Paneth cells.
Sympathetic Noradrenergic Fibers as the Source of Immunoreactive Alpha-Neoendorphin and Dynorphin in the Guinea Pig Heart
Authors: Wegener K. , Kummer W.
Published: July 2008

Dynorphin and α-neoendorphin bind to the K subtype of opioid receptors and have been shown to inhibit the release of noradrenaline from cardiac sympathetic axons. The purpose of this study was to elucidate the endogenous localization of dynorphin and α-neoendorphin in the guinea pig heart. This goal was achieved by double- and triple-labelling immunofluorescence. Dynorphin- and α-neoendorphin-immunoreactive nerve fibers were numerous around coronary blood vessels and among cardiomyocytes. They also contained immunoreactivities to the rate-limiting enzyme of catecholamine synthesis tyrosine hydroxylase and to neuropeptide Y. These fibers disappeared in response to chemical sympathectomy (6-hydroxydopamine treatment). In contrast, substance P/calcitonin gene-related peptide-immunoreactive axons of sensory origin did not contain dynorphin and α-neoendorphin immunoreactivities and were unaffected by chemical sympathectomy. The findings demonstrate that immunoreactive dynorphin and α-neoendorphin are contained in postganglionic sympathetic nerve fibers innervating coronary blood vessels and cardiac muscle. Therefore, the inhibitory effect of these peptides upon noradrenaline release from the sympathetic terminal may well be an autoinhibitory feedback loop.
A Morphological Study of the Primary Cilia in the Rat Pancreatic Ductal System: Ultrastructural Features and Variability
Authors: Bertelli E. , Regoli M.
Published: July 2008

Primary cilia in the pancreas of the rat were studied by transmission electron microscopy. Their presence is very common, and each ductal cell seems to be provided with a single cilium. The basal body showed anchoring apparatus such as transitional fibers and basal feet. The shaft can show a number of different patterns according to the level of the sections. Proceeding towards the tip, the microtubules decrease in number, although not always in the same way. Near the tip, it is possible to detect patterns with only 1 microtubule. Three kinds of tips are described. The function of the cilia is discussed.
An Ultrastructural Study of Epithelium Differentiation in the Human Fetal Fallopian Tube
Authors: Barberini F. , Makabe S. , Correr S. , Luzi A. , Motta P.M.
Published: July 2008

The epithelial structure of the developing human fetal Fallopian tube has been studied systematically by parallel light, transmission and scanning electron microscopy. The specimens for this study were collected from spontaneous abortions at the 14th, 18th, 20th and 22nd weeks and from cases of intrauterine fetal death at the 24th and 31st weeks (hydrocephalus). The epithelium lining the wall of the female genital ducts was pseudostratified in a columnar fashion. It consisted of differentiating ciliated and microvillous cells and some degenerating elements. Microvillous cells – by far the most abundant in the early phases of tubal development – often showed a solitary cilium. Ciliated elements, though always less numerous than microvillous cells, were more densely concentrated on the developing fimbriae and at the uterotubal junction than in the ampulla. On the mucosal surface of the same regions, rounded intercellular holes delimited many crypts, from which ciliated elements sometimes sprouted. Notable aspects of cell proliferation and ciliogenesis were commonly observed and are likely to be related to circulating estrogens. These ultrastructural data indicate that the typical pattern of the adult oviduct is already sketched in fetal life. Furthermore, a strategic gathering of cilia was noted primarily at the sites of the developing oviduct, which will serve to mediate the passage of sperm and/or ova and promote fertilization in adult life.
Immunohistochemical Study of the Distribution of Endocrine Cells in the Gastrointestinal Tract of the Lesser Mouse Deer (Tragulus javanicus)
Authors: Agungpriyono S. , Yamada J. , Kitamura N. , Yamamoto Y. , Said N. , Sigit K. , Yamashita T.
Published: July 2008

The occurrence and distribution of endocrine cells in the gastrointestinal tract of the lesser mouse deer, Tragulus javanicus were studied immunohistochemically. Fourteen types of endocrine cells immunoreactive for serotonin, somatostatin, enteroglucagon, pancreatic glucagon, bovine pancreatic polypeptide (BPP), gastrin, substance P, motilin, gastric inhibitory polypeptide (GIP), cholecystokinin (CCK), methionine-enkephalin-Arg6-Gly7-Leu8 (MENK-8), secretin, neurotensin, peptide tyrosine tyrosine (PYY) and chromogranin were revealed. Chro-mogranin-, serotonin-, somatostatin- and enteroglucagon-immunoreactive cells were detected in all regions examined, while pancreatic glucagon-immunoreactive cells, except in the proper gastric gland region, were not found in other regions of the gastrointestinal tract. Few BPP-immunoreactive cells in either the proper gastric gland or pyloric gland regions and abundant gastrin-immunoreac-tive cells in the pyloric gland region were observed. Restricted distributions of substance P-, GIP-, gastrin-, motilin-, CCK-, MENK-8-, secretin-, neurotensin- and BPP-immunoreactive cells in the small intestine, and BPP-, substance P-, PYY- and motilin-immunoreactive cells in the large intestine were noted. The important findings include the presence of BPP-immunoreactive cells in the abomasum, pancreatic glucagon-immunoreactive cells in the proper gastric gland region, and substance P- and motilin-immunoreactive cells in the large intestine. It is suggested that the distribution pattern of gut endocrine cells in the lesser mouse deer is more similar to that in the pig than in the domestic ruminants so far reported.
Adenohypophysial Morphology in Transgenic Dwarf Mice with Cerebral Production of Human Growth Hormone
Authors: Stefaneanu L. , Kovacs K.
Published: July 2008

In transgenic mice with cerebral expression of foreign GH, pituitary GH production is profoundly disturbed, blood IGF-I levels are decreased and growth is retarded. Adenohypophysial morphology in these transgenic mice (6 males and 6 females) was studied by immunocytochemistry, in situ hybridization and electron microscopy. In both sexes, GH immunoreactive cells were smaller, and reduced in number by about 50% compared to controls; the decrease of GH mRNA signal was stronger in males than in females and by electron microscopy, the somatotrophs had the features consistent with suppressed endocrine activity. In both sexes, PRL immunoreactive cells were slightly decreased in number; in male pituitaries PRL mRNA signal was weak and ultrastructurally, only lactotrophs with small secretory granules were found. In the adenohypophyses of females, the intensity of hybridization signal for PRL mRNA was unchanged and ultrastructurally, the lactotrophs were slightly decreased in size and contained increased number of phagolysosomes. The number of ACTH immunoreactive cells was increased in males; however, the intensity of POMC mRNA was unchanged. The increase in number of LH immunoreactive cells appeared to be more pronounced in males. These changes resemble but are less prominent than those seen in mice transgenic for MT/hGH in which hGH is produced in many tissues, blood hGH and IGF-I are elevated and gigantism develops. Pituitary alterations are attributed to the indirect effects of hGH which is both somatotropic and lactogenic in mice.
Morphology of the Retromandibular Vein in Relation to the Facial Nerve in the Parotid Gland
Authors: Kopuz C. , Ilgi S. , Yavuz S. , Önderoǧ;lu S.
Published: July 2008

In order to help avoid complications of parotid surgery, we investigated the relationship between the facial nerve and the retromandibular vein. Fifty dissections were performed on 30 cadavers. In 45 (90%) of the cases the retromandibular vein was located on the medial side of the upper and lower trunks of the facial nerve, and in 5 (10%), the course of the retromandibular vein was lateral to the lower trunks and medial to the upper trunks. These variations were divided into subgroups. The most commonly encountered variation was that the retromandibular vein crossed the facial nerve from the medial (34 cases) or lateral side (3 cases) at a point between the bifurcation and ramification points of the lower facial trunk. In one case, the retromandibular vein was detected on the lateral side of the facial nerve at the bifurcation. In 3 cases (15%), the course of the retromandibular vein was different on the right and left sides of the face in the same cadaver.
Fibronectin Penetration into Heart Myocytes Subjected to Experimental Ischemia by Coronary Artery Ligation
Authors: Frøen J.F. , Larsen T.H.
Published: July 2008

Using confocal microscopy and immunocytochemistry we have studied early changes in distribution of fibronectin (FN) in myocardial cells of rats subjected to experimental acute myocardial ischemia (AMI) by coronary ligation for several periods of 0.5 h to 6 days. In sham-operated and nonoperated rats, FN was present in the interstitium around the myocytes, and in their transverse tubules (TT). Already after 0.5 h of ischemia there was a well-defined increase of immunoreactive FN in focal areas of the interstitium of the hypoperfused portion, and distinct penetration into adjacent myocytes. The early penetration of FN into myocytes appears to follow a path through the TT, with a codistribution with actin in the I bands. This process precedes a total and diffuse infiltration of FN into the cytoplasm of disintegrating myocytes at later stages of coronary occlusion.
An Immunohistochemical Study on Cutaneous Sensory Receptors after Chronic Median Nerve Compression in Man
Authors: Ramieri G. , Stella M. , Calcagni M. , Cellino G. , Panzica G.C.
Published: July 2008

Carpal tunnel syndrome represents the most frequent chronic compressive neuropathy in man and hence may be investigated as a spontaneous model of peripheral nerve damage and repair. In the present report the fate of nerve fibers in the digital skin after long-lasting median nerve compression has been investigated immunohistochemically in comparison to normal digital skin, with special consideration to sensory endings and encapsulated receptors. The presence has been documented of the neurospecific marker PGP 9.5, the glia-associated protein S-100, and the neuropeptides CGRP and CPON which are mainly associated with the sensory and sympathetic nerve fibers respectively. The morphology and distribution of nerve fibers and corpuscles appeared comparable to that of normal digital skin; a reduction in the density of sensory receptors has, however, been observed, although not to the degree that was expected to explain the clinical deficits. It has been also demonstrated that at least part of the CGRP-containing sensory and CPON-containing sympathetic axons may survive unaltered even in patients with a long clinical history of profound sensorial impairment. An apparent discrepancy between the maintenance of nerve fibers and the sensory disturbances and the frequent observation of prompt postoperative recovery even after years of compression results from this investigation. The correlation of immunohistochemical observations and functional scores may not be considered conclusive. It must, however, be discussed if the sensorial impairment in this syndrome might have, at least in some cases, not only an anatomical but also an electrophysiological basis.
Innervation of the Human Vaginal Mucosa as Revealed by PGP 9.5 Immunohistochemistry
Authors: Hilliges M. , Falconer C. , Ekman-Ordeberg G. , Johansson O.
Published: July 2008

In order to obtain a description of the innervation of the vaginal wall we employed an antiserum against the general neuronal marker, protein gene product 9.5, on normal human vaginal mucosa. Specimens were taken from the anterior and posterior fornices, from the anterior vaginal wall at the bladder neck level and from the introitus vaginae region, and then processed for indirect immunohistochemistry. All regions studied revealed a profound innervation, although regional differences were noted. The more distal areas of the vaginal wall had more nerve fibers compared to the more proximal parts. Also, biopsies from the anterior wall generally were more densely innervated than the posterior wall. Some large nerve coils were observed in lamina propria of the anterior wall as well as gatherings of thick-walled medium-sized blood vessels. Free intraepithelial nerve endings were only detected in the introitus vaginae region. These fibers were very thin, always varicose and could be observed just a few cell layers from the surface. In this part of the vagina, protein gene product 9.5 anti¬bodies also stained cells within the basal parts of the epithelium. These cells were also neurone-specific enolase positive and resembled, from a morphological point of view, Merkel cells.
Distribution Pattern of F-Actin, Vimentin and Alpha-Tubulin in the Bovine Testis during Postnatal Development
Authors: Wrobel K.-H. , Bickel D. , Kujat R.
Published: July 2008

The distribution of F-actin, vimentin and α-tubulin was studied immunohistochemically in bovine seminiferous and straight testicular tubules, rete testis and intertubular tissue during postnatal development. Sites of antigenicity were detected by ABC immunoperoxidase technique and visualized by metal-enhanced deposition of diaminobenzidine. Within the seminiferous epithelium, F-actin appears at 20 weeks and is found in adult Sertoli cells as part of specialized cell contacts. In peritubular cells, F-actin increases gradually from 4 to 30 weeks when the adult concentration is achieved. After 20 weeks, subepithelial fibro-blasts of the mediastinum testis start to express F-actin and at 52 weeks, a thick layer of positive myofibroblasts is seen beneath the epithelia of rete testis and straight testicular tubules. Testicular macrophages and light intercalated cells (LIC) are also characteristically decorated following F-actin immunoreaction. Vimentin is localized in perinuclear position in pre-Sertoli cells of 4-20 weeks and in adult Sertoli cells. During the period of transformation from pre-Sertoli to Sertoli cells, the perinuclear vimentin coat is absent. The epithelia of rete testis and straight tubules exhibit a strong vimentin immunoreaction in their basal parts. This specific pattern does not change from 4 weeks to adulthood. α-Tubulin is absent in 4-week-old seminiferous tubules. At 8 weeks, the perinuclear area of pre-Sertoli cells reacts positive. The α-tubulin content increases in these cells continuously, and from 30 weeks on nearly the entire supranuclear cytoplasm of Sertoli cells is heavily decorated. The epithelial of rete and straight tubules display a growing number of α-tubulin-positive cells from 4 to 40 weeks. From then on, nearly all epithelial cells contain α-tubulin, particularly in a narrow zone beneath their lateral cell borders.
Neuroepithelial Bodies in Relatively Mature Lungs: An Investigation in Prenatal and Newborn Lambs
Authors: Van Lommel A. , Lauweryns J.M. , Marcus M. , Vertommen J.D.
Published: July 2008

Lungs of fetal and neonatal lambs were found to contain small, inconspicuous and widely dispersed neuroepithelial bodies (NEB). Under the light microscope, NEB could only be identified with certainty by their positive immune reaction to antibodies against serotonin. At the ultrastructural level, a large number of dense-cored vesicles was found in the corpuscular cells of the NEB. However, the number of intracorpuscular nerve endings was small. We conclude from these findings that, in the lamb, NEB act primarily as local regulators of lung function and that their reflex-mediated actions may be of secondary importance. This may be related to the fact that lungs of lambs at birth are relatively mature compared to those of various other species. Increased maturation of lungs and a concomitant decreased risk of insufficient oxygenation might be associated with the presence of an oxygen-sensitive chemoreceptor with primarily local actions for prevention of hypoxia.
Effect of Denervation on Morphogenesis of the Rat Fungiform Papilla
Authors: Nagato T. , Matsumoto K. , Tanioka H. , Kodama J. , Toh H.
Published: July 2008

In an attempt to elucidate the effects of denervation on development and maintenance of the structure of the fungiform papilla, unilateral neurectomy of the chorda tympani-lingual nerve of rats was performed at day 1 and at weeks 1, 2, 3, 4, 7, and 10 after birth. Specimens were obtained at days 3, 7 and 10, weeks 2, 3, 4, 6, and 8, and months 3 and 4 after neurectomy for examination by light and scanning electron microscopy. At first, the fungiform papillae were atrophic, then progressed to forms resembling filiform papillae. When an immature fungiform papilla was denervated, it eventually changed to a papilla identical to normal filiform papillae. The elicited changes differed according to the time of neurectomy; it was found that early neurectomy resulted in a more rapid and marked morphological change of the fungiform papillae. The filiform-like papillae derived from the fungiform ones showed various shapes, sizes, and orientations and were rarely present on the unoperated control side of the lingual dorsum. Sections of the filiform-like papillae revealed that they had no taste buds. These findings suggest: (1) Morphogenesis and structural maintenance of the fungiform papillae require the presence of the chorda tympani and/or lingual nerve. (2) Completion of differentiation and maturation differ in time among fungiform papillae. (3) Fungiform papillae may be transformed filiform papillae induced and maintained by a neurotrophic factor or factors coming from the chorda tympani and/or lingual nerve. (4) Fungiform papillae are rarely innervated contralaterally.
Cell-Cell Adhesion Molecules in Epithelial-Mesenchymal Transformations
Authors: Prieto A.L. , Crossin K.L.
Published: July 2008

The functional units in most inductive and morphogenetic processes in the embryo are not single cells, but rather collectives of interacting cells that give rise to the tissues and organs. Cell adhesion molecules (CAMs) are involved in defining cell collectives and their borders as they interact during inductive events in morphogenesis. The expression patterns of CAMs are highly dynamic and changes are known to occur during epithelial-mesenchymal transformations. Alterations in CAM expression are correlated with changes in morphology. Conversely, experimentally induced changes in morphology result in changes in CAM expression. The structure, function, distribution, and control of CAM gene expression are presented in this review, and discussed with regard to their importance to normal developmental processes, particularly epithelial-mesenchymal transformations.
A Subset of SBA Lectin-Binding Proteins Isolated from Myocardial-Conditioned Media Transforms Cardiac Endothelium into Mesenchyme
Authors: Sinning A.R. , Hewitt C.C. , Markwald R.R.
Published: July 2008

It has been shown that the inductively active proteins for cardiac mesenchyme formation are localized to a particulate form of extracellular matrix that resembles adheron-like complexes. These complexes are extractable from the embryonic heart using EDTA and can be visualized with the lectin SBA (Glycine max). In addition, the growth medium obtained from embryonic myocardial cell cultures has also been shown to support mesenchyme formation. However, except for the identification of EDTA extract and conditioned media, all previous experiments analyzing this system have relied on negative type results (i.e. the loss of biological activity) to show a relationship between the particulate matrix and the transformation process. We report here that SBA affinity chromatography can be used to partially purify a subset of proteins from myocardial conditioned medium which elicits the transformation of endothelial cells into mesenchyme. In addition, a polyclonal antibody made against this subset of proteins is specific for the in situ particulate matrix and recognizes several proteins in conditioned medium and EDTA extracts. This antibody is also specific for matrix particulates in other aeas of the embryo that undergo an epithelial/mesenchymal interaction. These results provide the most direct evidence to date that conditioned medium is equivalent to the hypothesized inductively active particulate matrix. In addition, the data provides evidence that conditioned medium can be used to identify the functional role of the components of the particulate matrix in mesenchyme formation.