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T Renda

Publications and source records attributed to T Renda.

At least 19 recordsLinked to original sources
PubMed2006

Early development of chick embryo respiratory nervous system: an immunohistochemical study.

The extrinsic and intrinsic respiratory nervous systems receive specific contributions from the vagal and sympathetic components. Using specific markers for vagal and sympathetic structures, we studied the distribution patterns of immunoreactivity to galanin (GAL), pituitary adenylate cyclase-activating polypeptide-27 (PACAP) and the tachykinin substance P in extrinsic and intrinsic nerve of chick embryo respiratory system, during development from the very early age to hatching. All peptides studied appeared in the intrinsic and extrinsic nervous systems early. We found substance P in both the vagal and sympathetic systems, PACAP in vagal components alone and GAL mainly in the sympathetic system. The intrinsic nervous system showed high immunoreactivity for all peptides studied. These data accord with the well known early trophic functions that peptides have on the development of nervous networks and modulatory activity on the intrinsic nervous system. The GAL again proves to be the main peptide in chick embryo sympathetic respiratory system.

Animals↗
PubMed2004

Nervous system development in normal and atresic chick embryo intestine: an immunohistochemical study.

Intestinal motility disorders are a common complication after surgery for neonatal intestinal atresia. Although intestinal atresia causes alterations in the enteric nervous system, especially in its inner structures (nervous fibers in the mucosa, submucous and deep muscular plexuses), how these alterations develop is unclear. The chick model is a useful research tool for investigating the ontogenesis of the enteric nervous system and the pathogenesis of congenital bowel diseases. More information is needed on the overlap between the developing enteric nervous system and intestinal atresia. Because vasoactive intestinal polypeptide and substance P are typical intestinal neuropeptides, and vasoactive intestinal polypeptide acts as a modulator in neurodevelopment and an inhibitor of smooth muscle cell proliferation, our aim in this study was to investigate the distribution of their immunoreactivity in the developing enteric nervous system of normal and experimental chick models. We studied gut specimens excised from normal chick embryos (aged 12-20 days) and experimental chick embryos (aged 15-20 days) that underwent surgical intervention on day 12 to induce intestinal atresia (atresic embryos) or simply to grasp the bowel loop (sham-operated embryos). In normal chick embryos we showed vasoactive intestinal polypeptide and substance P immunoreactivity from day 12 in the submucous and myenteric plexuses. The distribution of peptide immunoreactivity differed markedly in atresic and normal or sham-operated gut embryos. These differences especially affected the inner structures of the enteric nervous system of specimens proximal to atresia and were related to the severity of dilation. Because nerve structures in the gut wall mucosa and submucous and deep muscular plexuses play a role in motility control and stretch sensation in the intestinal wall, our findings in the chick embryo may help to explain how gut motility disorders develop after surgery for neonatal intestinal atresia.

Animals↗
PubMed2001

Fetal alveolar epithelial cells contain [D-Ala(2)]-deltorphin I-like immunoreactivity: delta- and mu-opiate receptors mediate opposite effects in developing lung.

Opiate-like peptides can regulate many cellular functions. We now map [D-Ala(2)]deltorphin I (DADTI)-like immunoreactivity (DADTI-LI) in developing mouse lung and analyze potential functional roles. Most DADTI-LI-positive cells were alveolar cells negative for prosurfactant protein (proSP)-C immunoreactivity. Peak numbers of DADTI-LI-positive cells occurred on embryonic Day 18, decreasing postnatally. To analyze developmental effects of DADTI, e17-18 lung explants were treated with [D-Ala(2)]deltorphin II (DADTII, soluble DADTI analogue, delta-receptor-specific) versus dermorphin (mu-receptor-specific). Type II pneumocyte differentiation, assessed by [(3)H]choline incorporation into saturated phosphatidylcholine and proSP-C immunostaining, was inhibited by DADTII but stimulated by dermorphin. Cell proliferation, measured as [(3)H]-thymidine incorporation and proliferating cell nuclear antigen immunostaining, was stimulated by DADTII and inhibited by dermorphin. All effects were dose-dependent. DADTII-inhibited choline incorporation was reversed by the delta-blocker, naltrindole. Unexpectedly, DADTII-stimulated thymidine incorporation was augmented by naltrindole and reversed by naloxone (mu-blocker). Although dermorphin-stimulated choline incorporation was appropriately blocked by binaltorphimine, dermorphin-inhibited thymidine incorporation was reversed by delta, kappa-, or mu-blockers. The delta- and mu-receptor messenger RNAs occurred pre- and postnatally, whereas kappa-receptor transcripts occurred mainly prenatally. All three receptor proteins were present in epithelial and mesenchymal cells in e18 lung. Thus, DADTI-LI from proSP-C-immunonegative alveolar cells could regulate development via both direct and indirect effects involving multiple opiate receptors.

Animals↗
PubMed2000

Glutathione S-transferase, similar to sigma class, from skin secretions of Xenopus laevis.

Using glutathione affinity chromatography followed by isoelectrofocusing, we purified from the skin secretion of Xenopus laevis an isoenzyme of glutathione S-transferase with an apparent subunit molecular mass of 22.5 kDa and an isoelectric point at pH 5.1. Its N-terminal amino acid sequence was highly similar to that of the sigma class glutathione S-transferase, which previously was demonstrated to have a glutathione-dependent prostaglandin D2 synthase activity. Immunohistochemistry analysis revealed that the isoenzyme was located in the cytoplasm of granular gland cells.

Amino Acid Sequence↗
PubMed1996

Heterogeneous distribution of fibronectin, tenascin-C, and laminin immunoreactive material in the cumulus-corona cells surrounding mature human oocytes from IVF-ET protocols--evidence that they are composed of different subpopulations: an immunohistochemical study using scanning confocal laser and fluorescence microscopy.

Monoclonal antibodies and immunofluorescence microscopy, including laser confocal microscopy, were used in this study to point out the production of fibronectin, tenascin-c, and laminin in the cumulus-corona (CC) cells surrounding mature human oocytes from IVF-ET protocols in view of their presumptive importance in the coordination of the processes leading to fertilization and early embryo cleavage, including the final maturation of the ovum, the sperm-egg interaction, and the "complex biochemical dialogue" between the gamete and the oviduct through the tubal luminal environment. One hundred fifty mature oocyte-CC complexes were obtained from IVF-ET protocols and fixed in 4.0% buffered paraformaldehyde. Specimens were incubated with a panel of primary monoclonal antibodies (mabs) recognizing different epitopes of fibronectin, tenascin-c, and laminin and then with fluorescein isothiocyanate-conjugated goat anti-mouse IgG. Observations were made by a scanning confocal microscope (Sarastro 2000) and a photomicroscope (Polyvar, Reichert-Jung) equipped with epifluorescence optics. The immunohistochemical data demonstrated that human CC cells are capable of producing fibronectin and tenascin-c but that their production is not homogeneous in the CC population. In fact, fibronectin immunoreactivity was shown mostly by inner CC cells (mainly corona cells), whereas tenascin was produced by some cells scattered in the entire cumulus mass. Moreover, fibronectin and tenascin-c immunoreactive material was observed in the intracytoplasmic areas, at the plasma membrane level as well as in the extracellular matrix. On the contrary, laminin immunofluorescent material was found around plasma membranes of almost all CC cells, but a clear intracytoplasmic reaction was never observed. This leads us to assume that laminin in the extracellular matrix remains entrapped once produced by granulosa follicular cells and that in the postovulatory period no active secretion occurs in CC cells. Even though the functional role of these extracellular matrix proteins remains still unclear, it is reasonable to suggest that they are necessary in various steps of the reproductive process, i.e., from the pick-up of the oocyte, its transport through the oviduct, and fertilization, up until the early cleavage of the embryo. Finally, functional differences between "corona radiata" and "cumulus" cells during the oocyte denudation may be accounted for particular distribution of these adhesive proteins.

Fertilization in Vitro↗
PubMed1995

Phylogenetic study on distribution and chromogranin/secretogranin content of histamine immunoreactive elements in the gut.

The distribution of histamine-immunoreactive (HA-IR) elements and possible coexistence of chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII) were immunohistochemically studied in gut specimens of various vertebrate species. In fish, HA-IR cells were distributed mainly within the gastric and duodenal mucosa, and nerve fibres in the gastric myenteric plexus. Only the gastric HA-IR cells co-stored SgII. In frog specimens, HA-IR endocrine cells and nerve fibres were found in the distal stomach wall, but SgII coexisted only in the nerve fibres. In lizard, HA-IR endocrine cells were widely distributed from the oesophagus to the small intestine, but only those in the stomach co-stored CgA, CgB and SgII. In chick, HA-IR cells were found in the proventriculus and almost all co-stored all three proteins. In rat, HA-IR cells were accumulated in the oxyntic mucosa and all of them constantly immunostained for CgA only.

Animals↗
PubMed1994

Postnatal development of [D-Ala2]deltorphin-I-like immunoreactive structures in the rat brain.

[D-Ala2]deltorphin-I, a highly selective ligand for delta opioid receptors, is a heptapeptide originally purified from frog skin. Previous immunohistochemical studies indicate that [D-Ala2]deltorphin-I-like molecule(s) may be present in adult rat brain, including specific neuronal cells and fibers partially overlapping with the mesocortical and nigrostriatal dopaminergic systems. Here, we examined the developmental aspect of such immunoreactive brain structures in early postnatal rats. In newborn to 21-day-old rats, positive staining in the brain occurred mainly in subpopulations of neurons and occasionally in tanycytes. On postnatal day 0, neuronal cell bodies containing [D-Ala2]deltorphin-I-like immunoreactivity were found in various brain regions, including the olfactory tubercle, ventral pallidum, hippocampus, ventral tegmental area, pars compacta of the substantia nigra, supramammillary nucleus, and dorsal raphe nucleus. Immunoreactive nerve fibers were observed in the main and accessory olfactory bulbs, olfactory tubercle, prelimbic area, anterior cingulate cortex, neostriatum, accumbens, lateral septal nucleus, lateral habenular nucleus, and superior colliculus. As pups grew, positive staining of cell bodies decreased gradually in both density and intensity, and those in the olfactory tubercle and ventral pallidum were no longer visible on postnatal day 14. On postnatal day 21, positive cells were found only in the ventral midbrain, including the pars compacta of the substantia nigra, ventral tegmental area, A8 region, and supramammillary nucleus. Positive fibers also decreased in density with age except in the accessory olfactory bulb, olfactory tubercle, prelimbic area, and anterior cingulate cortex.

Amino Acid Sequence↗
PubMed1994

Localization of [D-Ala2]deltorphin I-like immunoreactivity in perinatal rat respiratory system.

The localization of [D-Ala2]deltorphin I, a delta-opioid receptor ligand, was studied in the lower respiratory tract of developing rats using an immunohistochemical method. [D-Ala2]-like immunoreactive cells were detected first in the principal bronchus as early as embryonic day 16. As embryos grew, positive cells became gradually visible everywhere from principal bronchi to respiratory bronchioles. The density of positive cells reached the highest level on embryonic day 21, but decreased gradually after birth. Positive cells were no longer seen on postnatal day 30 in any region of the airways. No positive cells were ever found in the trachea or alveoli of rats at any age studied. Ultrastructural examination indicated that the immunoreactive cells possessed a similar morphology to serous or Clara cells of the respiratory epithelium. Immunoreaction products tended to locate at the apical cytoplasm of positive cells. The results suggests that [D-Ala2]-like molecule(s) may be expressed transiently in serous cells or Clara cells, or both, of the rat bronchopulmonary tract. Such a molecule may act as a pulmonary growth-promoting or a differentiation-initiating factor in an early period of lung development.

Animals↗
PubMed1994

Immunohistochemical localization of chromogranin A and B in the endocrine cells of the alimentary tract of the green frog, Rana esculenta.

Novel monoclonal antibodies to human chromogranin A (CgA) and chromogranin B (CgB) were used to investigate the presence of immunoreactive (-IR) elements in the alimentary tract of the green frog Rana esculenta. Numerous CgA-IR and a few CgB-IR endocrine cells were found within the gut mucosa, from the oesophagus to the cloaca, with some local differences in density. Co-localization studies demonstrated that they were co-stored in almost all the serotonin-IR, the amylin-IR or islet amyloid polypeptide-IR cells and in the peptide tyrosine tyrosine-IR cells located proximal to the pylorus, but not in those located in more caudal tracts. No other co-localization was demonstrated; substances investigated included somatostatin, substance P, gastrin/cholecystokinin, glucagon, glycentin, bombesin, secretin and neurotensin. CgA-IR and CgB-IR cells nearly always displayed argyrophilia with the Grimelius silver method.

Amyloid↗
PubMed1994

Demonstration of [D-Ala2]deltorphin I-like immunoreactivity in mucosal epithelial cells of the rat gastrointestinal tract.

Using a specific antiserum to [D-Ala2]deltorphin I (DADTI), a delta-opioid receptor ligand, the localization of positive structures was studied in rat gastrointestinal tract by immunocytochemistry. Immunoreactive staining was not detected in the stomach, colon, or neuronal elements of any gastrointestinal tissue. However, positive cells were distributed in the mucosal epithelium of the small intestine, including the duodenum, jejunum, and ileum. The density of positive cells was highest at a proximal part of the jejunum and was gradually decreased toward the duodenum or the distal end of the intestine. These positive cells had spindle-like somata that tended to locate more closely to the lumen compared with nonimmunoreactive cells. Some of the positive cells extended cytoplasmic basal processes toward the lamina propria. Immunoelectron microscopy revealed that positive reaction products occurred within the secretory granules as well as in the cytoplasm. Because these positive granules were frequently observed in the apical cytoplasm beneath the microvilli, it is suggested that the DADTI-like molecule(s) may be secreted to the lumen.

Amino Acid Sequence↗
PubMed1994

Immunohistochemical demonstration of [D-Ala2]deltorphin-I in amacrine cells of rat retina.

In an immunohistochemical study, a specific antiserum raised against [D-Ala2]deltorphin-I (DADTI), a highly selective ligand for delta opioid receptors, was used to demonstrate immunoreactive structures in the rat retina. [D-Ala2]Deltorphin-I immunoreactivity occurred in a subpopulation of the retinal amacrine cells situated in the inner nuclear layer. Their stained processes were mainly distributed in the sublaminae 1 and 3 of the inner plexiform layer. A few positive cells, probably displaced amacrine cells, were also seen in the ganglion cell layer. Double immunostaining revealed that 12.8% of DADTI-immunoreactive cells costored GABA and 27.7% costored neuropeptide Y, whereas only few DADTI-positive cells colocalized tyrosine hydroxylase (0.3%) and almost no other peptides. These findings suggest that some retinal amacrine cells possess DADTI-like molecule(s), possibly acting as neurotransmitter(s) or neuromodulator(s).

Amino Acid Sequence↗
PubMed1994

Transient expression of [D-Ala2] deltorphin I-like immunoreactivity in prenatal rat small intestine.

We studied the distribution of immunoreactive elements for [D-Ala2] deltorphin I (DADTI), a delta-opioid receptor ligand, in fetal and postnatal rat small intestine. DADTI-like immunoreactive cells were detected transiently on embryonic Days 20 and 21. Electron microscopic examination revealed that positive staining occurred in mucous epithelial cells, either mature goblet cells or undifferentiated cells containing only a few mucous granules. Positive immunoreaction products in mature goblet cells were confined in their apical cytoplasm to the luminal parts of mucous granule aggregates. The result suggests that a DADTI-like molecule(s) is synthesized in rat intestinal goblet cells and is secreted in a diacrine fashion into the intestinal lumen at a late fetal period. The molecule(s) thus secreted may be important for the intestine of rats just before birth, because DADTI-like immunopositive goblet cells are no longer seen at any postnatal period.

Amino Acid Sequence↗
PubMed1994

Phylogenetic aspects of the occurrence and distribution of secretogranin II immunoreactivity in lower vertebrate gut.

A novel monoclonal antibody raised against bovine secretogranin II (Sg II) was used in immunohistochemical studies on amphibian (Rana esculenta), reptilian (Podarcis sicula) and avian (Gallus gallus) gut. Sg II immunoreactivity was detected in epithelial and nervous elements. Cells immunoreactive for Sg II were examined by double immunostainings to determine whether they might also co-store certain previously known bioactive amine/peptide substances. Almost all the endocrine cells immunoreactive for bombesin, substance P, neurotensin, gastrin/cholecystokinin, neuropeptide tyrosine (NPY) and calcitonin gene-related peptide as well as some of those immunostained for serotonin, histamine, and polypeptide tyrosine tyrosine (PYY) also contained Sg II. Sg II-immunoreactive cells varied in number and distribution according to regions of the gut and animal species. The number of Sg II immunoreactive granules notably varied not only according to cell type, but also within the same cell population. Many histamine-, calcitonin gene-related peptide (CGRP)-, substance P-, PYY-, and neurotensin-immunoreactive neurons also contained Sg II. These were mostly situated in the myenteric plexus; their distribution pattern varied among the three species. These findings show that, despite being well conserved during phylogeny, Sg II has a heterogeneous distribution.

Animals↗
PubMed1994

Circulating D dimer in inflammatory bowel disease.

An activated thrombogenesis has been reported in inflammatory bowel disease (IBD). In this study we evaluated whether a fibrin degradation product, the D dimer, is increased in patients with IBD. D dimer plasma levels were evaluated by sandwich ELISA in patients with Crohn's disease (24), ulcerative colitis (25), gastrointestinal (GI) disease controls (10), hospital controls (13) and healthy subjects (14). Circulating D dimer was significantly higher in ulcerative colitis (median 651; 95% CI 89-1275 ng/ml) than in healthy subjects (median 412; 95% CI 112-672 ng/ml; p = 0.002), Crohn's disease (median 466; 95% CI 6-931 ng/ml; p = 0.005) and GI disease controls (median 446; 95% CI 196-688 ng/ml; p = 0.023). In ulcerative colitis, plasma D dimer was related to inflammatory parameters such as C-reactive protein (p < 0.01) and seromucoids (p < 0.001). Circulating D dimer was age-related in all groups (p < 0.05). Fibrin degradation, as reflected by plasma D dimer, is detected in patients with ulcerative colitis exhibiting a marked acute phase response.

Adult↗
PubMed1993

[d-Ala2]deltorphin I-like immunoreactivity in the adult rat brain: immunohistochemical localization.

Using a specific antiserum recently raised against [D-Ala2]deltorphin I (DADTI: Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2), a highly selective ligand for delta-opioid receptors, we have previously demonstrated the occurrence of positive immunostaining in several structures of mouse brain. We describe here the neuroanatomical distribution patterns of DADTI-immunoreactive neuronal bodies, axons, and tanycytes in rat brain. Positive neuronal somata were localized mainly in the ventral mesencephalon, including the ventral tegmental area and the pars compacta of the substantia nigra. A minor population of positive somata was found in the pars reticulata and pars lateralis of the substantia nigra, raphe nuclei, supramammillary nucleus, and retrorubral reticular nucleus. All these regions, except for the supramammillary nucleus, contain dopamine cell bodies. Intensely stained positive nerve fibers could be traced along the medial forebrain bundle. Dense positive terminals were seen in the neostriatum, nucleus accumbens shell, olfactory tubercle, septal areas, cingulate, and medial prefrontal cortex. Double-immunostaining study revealed that, in the substantia nigra, almost all (97.8%) DADTI-positive neurons colocalized with tyrosine hydroxylase (TH), and the doubly stained cells occupied about one-third (29.1%) of the total population of TH-positive neurons. Only a few DADTI/TH-positive cells also stained for 28-kDa calbindin D, although many neurons double-stained for 28-kDa calbindin D and TH. In contrast, the supramammillary nucleus contained a number of DADTI-positive cells, which nearly always stained positively for 28-kDa calbindin D but did not stain for TH. The association of DADTI-like immunoreactivity with certain dopaminergic pathways seems of particular interest. A small population of DADTI-immunostained tanycytes was present in the ventral part of the third ventricle wall.

Amino Acid Sequence↗
PubMed1993

Autoradiographic study on [3H]-[D-Ala2]-deltorphin-I binding sites in the rat brain.

Previous biochemical and pharmacological studies have shown that [D-Ala2]-deltorphin-I (DADTI) has a high affinity and selectivity for delta-opioid receptors. In this study, designed to provide morphological details, the distribution of DADTI binding sites was examined by autoradiography on coronal, sagittal and horizontal frozen sections of adult rat brain. The sections were incubated with tritiated DADTI solution and exposed for 12 weeks to a 3H-sensitive film. DADTI labelling clearly demonstrated selective and high affinity binding sites of delta-opioid type in several brain regions, including olfactory system, neostriatum, nucleus accumbens, and cortical layers I-II and V-VI.

Animals↗
PubMed1992

Production of antiserum to [D-Ala2]deltorphin I and its immunohistochemical application to the mouse brain.

Antiserum to haptenic [D-Ala2]deltorphin I (DADTI: Tyr-D-Ala-Phe-Asp-Val-Val-Gly.NH2), a highly selective ligand for delta opioid receptors, was produced in rabbits. By immunospot assay, the antiserum recognized 62.5 pmol DADTI but failed to react even with 4 nmol carrier protein of the immunogen. Although the antiserum reacted equally with an isomer [L-Ala2]deltorphin I, virtually no cross-reaction occurred with other analogues such as [D-Ala2]deltorphin II (Tyr-D-Ala-Phe-Glu-Val-Val-Gly.NH2) and similar peptides lacking the C-terminal glycine amide. Therefore, the major epitope for immunorecognition appeared to be in the C-terminal region which is known to be the specific domain for delta opioid receptor selectivity. Immunohistochemical study using this antiserum revealed positive neuronal structures in some specific systems of the mouse brain.

Amino Acid Sequence↗