Biomedical subjects

S Magari

Publications and source records attributed to S Magari.

At least 19 recordsLinked to original sources

PubMed1992

Distribution and possible origins of substance P-containing nerve fibers in the rat liver.

The distribution and possible origins of substance P-containing nerve fibers in the rat liver were investigated by immunohistochemistry and nerve transection. Nerve fibers with substance P-like immunoreactivity formed a more complex network than previously known in the walls of portal vein branches. Substance P-immunoreactive fibers were seen not only in and around the walls of the hepatic artery, but also in close association with the hepatic veins and bile ducts. Transection of the greater splanchnic nerves and/or the vagus nerves indicated that substance P-immunoreactive fibers in the walls of the portal and hepatic veins enter the liver via both nerves, and that those associated with the hepatic artery and bile ducts stem from the greater splanchnic nerves. The widespread distribution of hepatic substance P and its complex innervation pattern within the liver suggest that it is involved in a variety of physiological processes in this organ.

Animals↗

PubMed1991

Fine structure of substance P-containing nerve fibers in the rat lateral septum; simultaneous localization in pre- and postsynaptic elements.

The fine structure of nerve fibers with substance P (SP)-like immunoreactivity in the rat lateral septum (LS) was investigated by preembedding immunoelectron microscopy. SP axon terminals frequently made synapses with non-immunoreactive neuronal soma and dendrites in the LS. Occasionally, two closely apposed nerve endings with SP immunoreactivity were presynaptic to the soma. A small number of immunopositive axon terminals formed synapses not only with neuronal perikarya but also with small dendrites in the vicinity of the perikarya. There were also some SP dendrites in contact with immunoreactive as well as non-immunoreactive nerve endings. These findings may provide a morphological basis for the complexity of SP actions on septal neurons.

Animals↗

PubMed1991

Morphologic changes in detrusor muscles of patients with chronic obstruction of lower urinary tract. Electronmicroscopic and immunohistochemical findings.

The anterior bladder wall and actin- and myosin-like immunoreactivities within the detrusor muscles in patients with chronic obstruction of the lower urinary tract were examined by means of a MOP Videoplan image-processing system, electronmicroscopy, and light microscopic immunohistochemistry. The image-processing system demonstrated an excess of connective tissue elements between smooth muscle bundles in the anterior wall of the bladder similar to the results of previous studies dealing with the trabeculated posterior wall. Under electronmicroscopy, myofilaments were shown to be multidirectionally arranged in the smooth muscle cells in contrast to the regular arrangement in controls. Dense areas in the cytoplasm of the detrusor muscle also appeared to be abnormally distorted and/or elongated in the electronmicrographs. In support of these findings, actin- and myosin-like immunoreactivities in the muscle layer of the bladder were significantly less intense than in the controls. These results suggest that chronic obstruction of the lower urinary tract causes histopathologic alterations in both the intervening connective tissue and the detrusor muscle. This study raises the possibility that the aforementioned morphologic abnormalities are involved in the occurrence of uninhibited detrusor contraction and abnormal detrusor reflex in patients with lower urinary tract obstruction.

Actin Cytoskeleton↗

PubMed1991

Lymphatics and pre-lymphatics of the rabbit pericardium and epicardium with special emphasis on particulate absorption and milky spot-like structures.

The lymphatics and pre-lymphatic connective tissue of rabbit pericardium and epicardium were examined by light and electron microscopy under normal conditions and after the injection of India ink and latex particles into the pericardial cavity. A characteristic lattice structure of connective tissue was present between the small mesothelial cells and the submesothelial lymphatic capillaries in the basal region of the pericardium, but not in the epicardium. Milky spot-like structures bulging toward the pericardial cavity were found in the pericardium, similar to those in the omentum and mediastinal pleura. Within 60 minutes after injection, carbon and latex particles were directly absorbed through the intercellular clefts of the adjacent small mesothelial cells into the submesothelial layer particularly at sites of characteristic lattice structure. Carbon particles were already present in the lumens of lymphatic capillaries at this time. Macrophages in the pericardial cavity and submesothelial layers of the pericardium engulfed both carbon and latex particles. Our results suggest two possible routes of drainage of particulate matter from the pericardial cavity into the lymphatics: direct absorption and indirect absorption after phagocytosis by macrophages. Macrophages probably migrate from the milky spot-like structures described in this study. Epicardial lymphatics, in contrast, drain tissue fluid primarily from the myocardium.

Absorption↗

PubMed1991

Immunoelectron microscopy of cell populations in regional and central lymph of sheep.

The immunoreactivity and the ultrastructural localization of monoclonal anti-sheep lymphocyte antibodies conjugated with colloidal gold particles were examined in free-floating cells of sheep central lymph from the thoracic duct, postnodal lymph draining either the popliteal nodes or the mesenteric nodes, and prenodal lymph draining the pregnant uterus. The monoclonal antibodies used in this study were SBU-T1 (CD5), SBU-T4 (CD4), SBU-T8 (CD8), SBU-II (anti DR antibody), and E53 which are reported to be sheep homologues of human T1, T4, T8, HLA-DR, and pan B cell antibodies, respectively. Colloidal gold particles were evenly distributed or segmentally aggregated on the surfaces of lymphocytes and macrophages incubated with monoclonal antibodies and in vesicles in the cytoplasm of anti DR antibody labeled macrophages. Not only did CD5 labeled cells show a high percentage in each regional lymph examined, but the percentage of CD4 labeled cells was consistently higher than that of CD8 labeled cells. Moreover, the immunoreactivity of CD8 labeled cells was specific among lymph from the different regions. The sum of the percentages of CD4 and CD8 labeled cells was less than the percentage of CD5 labeled cells, indicating the presence of a minor T cell subpopulation which was CD5+, CD4-, and CD8-. A characteristic finding was a high percentage of CD8 labeled cells and many abnormal eosinophils in uterine prenodal lymph in pregnant sheep. Taken together the results showed that variously labeled immunoreactive cells are distributed somewhat differently in lymph derived from different organ sites.

Animals↗

PubMed1990

Somatostatin co-localizes with tyrosine hydroxylase in the nerve cells of discrete hypothalamic regions in rats.

The co-expression of somatostatin (SOM)- and tyrosine hydroxylase (TH)-like immunoreactivities in nerve cells of the rat hypothalamus was investigated by the simultaneous application to the same sections of immuno-beta-galactosidase staining and the peroxidase-antiperoxidase (PAP) method. SOM-like immunoreactive cells stained blue with immuno-beta-galactosidase staining and TH-like immunoreactive cells stained brown with the PAP method. Double-labeled cells with overlapping blue and brown immunoreaction products were frequently identified in the preoptic periventricular nucleus (pope). These double-labeled cells were seen in clusters within the ventral half of the rostral pope. The periventricular hypothalamic nucleus at the level of the anterior hypothalamic nucleus contained only scattered nerve cells with both SOM- and TH-like immunoreactivities, despite the presence of many nerve cells immunoreactive for either SOM or TH in this nucleus. Double-labeled cells were also observed in some regions of the medial-basal hypothalamus, including the boundary between the ventromedial hypothalamic nucleus and the arcuate hypothalamic nucleus, and areas dorsal and lateral to the ventromedial hypothalamic nucleus. These findings may provide insight into the mechanisms underlying previously described catecholamine-mediated modulation of SOM release from the hypothalamus.

Animals↗

PubMed1990

Co-localization of arginine vasopressin- and enkephalin-like immunoreactivities in nerve cells of the rat hypothalamus.

The co-localization of arginine vasopressin- and enkephalin-like immunoreactivities in nerve cells of the rat paraventricular hypothalamic nucleus and adjacent areas was investigated by the simultaneous application of immuno-beta-galactosidase staining and the peroxidase-antiperoxidase method to sections. Arginine vasopressin-like immunoreactive cells were stained blue with immuno-beta-galactosidase staining and enkephalin-like immunoreactive cells brown with the peroxidase-antiperoxidase method. Double-labeled cells with overlap of blue and brown immunoreaction products were identified in the anterior, medial, and lateral parvocellular parts of the paraventricular hypothalamic nucleus as well as in the previously indicated posterior magnocellular part. Other regions that contained double-labeled cells were the lateral hypothalamic area, anterior hypothalamic nucleus, area between the lateral hypothalamic area and anterior hypothalamic nucleus, suprachiasmatic nucleus, and bed nucleus of the stria terminalis, medial division, posterolateral part. These findings suggest that nerve cells with both arginine vasopressin- and enkephalin-like immunoreactivities may be more actively involved in neuroendocrine regulation and neural transmission than previously considered. They may provide a morphological basis for an increase in enkephalin-like immunoreactivity within the anterior pituitary in cases of hemorrhagic shock which is presumably accompanied by arginine vasopressin hypersecretion.

Animals↗

PubMed1990

Immunogold-silver staining method for light and electron microscopic detection of lymphocyte cell surface antigens with monoclonal antibodies.

We used the immunogold-silver staining method (IGSS) for detection of lymphocyte cell surface antigens with monoclonal antibodies in light and electron microscopy and compared this procedure with the immunogold staining method. Two different sizes of colloidal gold particles (5 nm and 15 nm) were used in this study. Immunolabeling on cell surfaces was visualized as fine granules only by IGSS in light microscopy. The labeling density (silver-gold complexes/cell) and diameters of silver-enhanced gold particles on cell surfaces were examined by electron microscopy. Labeling density was influenced not by the enhancement time of the physical developer but by the size of the gold particles. However, the development of shells of silver-enhanced gold particles correlated with the enhancement time of the physical developer rather than the size of the colloidal gold particles. Five-nm gold particles enhanced with the physical developer for 3 min were considered optimal for this IGSS method because of reduced background staining and high specific staining in the cell suspensions in sheep lymph. Moreover, this method may make it possible to show the ultrastructure of identical positive cells detected in 1-micron sections counterstained with toluidine blue by electron microscopy, in addition to the percentage of positive cells by light microscopy.

Animals↗

PubMed1990

Immunoelectron-microscopic localization of peptidergic nerve fibers around lymphatic capillaries in the rat liver.

The localization of neuropeptide Y (NPY)-, substance P (SP)- and calcitonin gene-related peptide (CGRP)-containing nerve fibers around lymphatic capillaries (initial lymphatics) in the interlobular connective tissue of the rat liver was investigated by preembedding immunoelectron-microscopy. Nerve terminals with NPY were frequently seen in close apposition to the abluminal surface of lymphatic endothelium. A small number of NPY fibers without a glial (Schwann cell) covering at the tip ran toward lymphatic capillaries in the interlobular connective tissue. Nerve fibers immunoreactive for SP were present within unmyelinated fiber bundles that ran close to lymphatic capillaries in the interlobular connective tissue. Besides these immunoreactive nerve fibers, many of which appeared to pass through the subendothelial regions of lymphatic capillaries, scattered SP nerve endings were seen in areas contiguous to lymphatic endothelium. CGRP terminals were rarely found around lymphatic capillaries, although nerve fiber bundles containing CGRP components traversed close to some lymphatic capillaries. These findings suggest that NPY and SP, if released from nerve terminals into the subendothelial areas of adjacent lymphatic capillaries, are more likely to affect the metabolic activity of lymphatic endothelium and the flow (or formation) of lymph than CGRP. SP and CGRP, as possible mediators of sensory transmission, might be involved in the conveyance of information on the hydrostatic pressures of hepatic lymphatics and surrounding tissue fluid to the central nervous system.

Animals↗

PubMed1990

Immunohistochemical differentiation between lymphatic vessels and blood vessels--use of anti-basement membrane antibodies and anti-factor VIII-related antigen.

Several immunohistochemical methods using Factor VIII-Related antigen (FVIIIR:Ag), laminin, Type IV collagen and fibronectin antisera were applied for the purpose of differentiating rat lymphatics from blood vessels by light and electron microscopy. Weibel-Palade bodies (WPB) were demonstrated in both types of vessels by conventional electron microscopy. The immunoreactivity to laminin and Type IV collagen in blood vessels showed a strong, continuous, linear subendothelial staining pattern in contrast to lymphatic vessels in which immunoreactivity was absent or weak in paraffin-embedded sections stained with the indirect immunoperoxidase technique. A positive reaction for fibronectin was observed in all extra-vascular tissue spaces as well as in lymphatics and blood vessels. FVIIIR:Ag and WPB were present in both lymphatic and blood endothelial cells. FVIIIR:Ag antiserum labeled with gold particles was observed only in the vacuoles which were assumed to be identical with WPB as demonstrated by our conventional electron microscopy. We conclude that the immunohistochemical method using laminin and Type IV collagen antisera is a reliable and practical way to differentiate lymphatic vessels from blood vessels by light microscopy.

Animals↗

PubMed1990

Distribution of peptidergic nerve fibers in rat bronchus-associated lymphoid tissue: light microscopic observations.

The localization of neuropeptide Y (NPY), substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) in the nerve fibers of rat bronchus-associated lymphoid tissue (BALT) was investigated by light microscopic immunohistochemistry. Nerve fiber bundles revealing NPY-like immunoreactivity were shown to enter the BALT together with pulmonary artery branches. They frequently reached the central zone of the BALT to give rise to fine, tortuous fibers. On the other hand, nerve fibers immunoreactive for SP and CGRP seemed to distribute in the subepithelial zone of the BALT after dissociating from fiber networks in the walls of bronchi, although small numbers of SP and CGRP fibers were also seen in the BALT central zone. CGRP fibers formed a more intense network than SP fibers in the BALT. Scattered VIP fibers were found only in the subepithelial zone of the BALT. These findings not only suggest that the four kinds of peptidergic fibers act on BALT in multiple ways, but also that these neuropeptides may be involved in the control of mucosal immunity, lymphocyte migration and proliferation within the BALT.

Animals↗

PubMed1990

Lymphatics, intraepithelial lymphocytes and endometrial lymphoid tissues in the rabbit uterus: an electron microscopic and immunohistological study.

Rabbit uterine intraepithelial lymphocytes, endometrial lymphoid aggregates and lymphatic capillaries were examined electron-microscopically and immunohistochemically at well-defined intervals after the injection of human chorionic gonadotropin (hCG). Lymphatic capillaries originated near the bases of the glands in the uterine cervix and in the border zone between the lamina propria mucosae and myometrium in the uterine body. The lymphatic capillaries were maximally dilated, and their endothelial cells were thinnest 8 hours after hCG injection. Patent junctions between the adjacent endothelial cells of lymphatics in the uterine body were observed in good accordance with the appearance of stromal edema and lymphatic dilatation. The numbers of intraepithelial lymphocytes and macrophages changed cyclically after the induction of ovulation. They were highest 11 hours after hCG injection when lymphocytes were seen occasionally in the lumens of lymphatics located in the lamina propria mucosae of the uterine body. Most of the intraepithelial and interstitial lymphocytes were cells labeled with T cell serum but some were labeled with IgA serum and were occasionally seen beneath the epithelium. Lymphoid aggregates were uniformly present in the stratum basalis and consisted of lymphocytes and macrophages. They had no germinal centers, surrounding lymphatics or high endothelial venules (HEV). The results suggest that lymphatic capillaries are the main route for the removal of edema fluid and for migratory lymphoid cells in the rabbit uterus.

Animals↗

PubMed1989

Distribution, possible origins and fine structure of neuropeptide Y-containing nerve fibers in the rat liver.

The distribution, possible origins and fine structure of neuropeptide Y (NPY)-containing nerve fibers in the rat liver were investigated by immunohistochemistry, nerve transection and immunoelectron microscopy. Light-microscopic immunohistochemistry showed NPY fibers forming a complex network in and around the walls (tunica adventitia and tunica media) of hepatic vessels. They were also closely associated with interlobular bile ducts. The NPY fibers in the liver were almost completely eliminated by transection of the greater splanchnic nerves just distal to the celiac ganglion. Transection of the greater splanchnic nerves just proximal to the celiac ganglion resulted in a marked decrease in NPY fibers, but a significant number remained intact. Under electron microscopy. NPY terminals without a covering of glial processes were seen not only in proximity to smooth muscle cells within the tunica media of hepatic vessels but also in the subendothelial areas of the tunica intima. Some NPY axon terminals devoid of glial ensheathment were located close to the basal lamina of interlobular bile ducts. Occasionally, single axon terminals with NPY were found in the vicinity of or in contact with hepatic cells. There was a small number of NPY fibers that had lost their glial sheaths while running toward lymphatic capillaries. These findings suggest that hepatic NPY arises from the celiac ganglion and paravertebral sympathetic ganglia, and that it is involved in more complex physiological processes than the previously described neuropeptides in the liver, which are localized exclusively to hepatic vessel walls.

Animals↗

PubMed1989

Co-localization of corticotropin-releasing factor- and enkephalin-like immunoreactivities in nerve cells of the rat hypothalamus and adjacent areas.

The co-localization of corticotropin-releasing factor (CRF)- and enkephalin (ENK)-like immunoreactivities in nerve cells of the rat hypothalamus and adjacent areas was investigated by the simultaneous application of immuno-beta-galactosidase staining and the peroxidase-antiperoxidase (PAP) method to the same sections. CRF-like immunoreactive cells were stained blue with immuno-beta-galactosidase staining and ENK-like immunoreactive cells brown with the PAP method. Double-labeled cells with overlap of blue and brown immunoreaction products were identified in all subregions of the paraventricular hypothalamic nucleus (PVH), in contrast to previous studies showing the occurrence of double-labeled cells only in the parvocellular part of the PVH. Other areas that contained double-labeled cells were: the medial preoptic area, bed nucleus of the stria terminalis, periventricular hypothalamic nucleus, lateral hypothalamic area, dorsal hypothalamic area and subincertal nucleus. These findings suggest that nerve cells with both CRF- and ENK-like immunoreactivities may be more actively involved in neuroendocrine regulation and neural transmission than previously considered.

Animals↗

PubMed1989

Reassessment of enkephalin (ENK)-containing afferents to the rat lateral septum with reference to the fine structures of septal ENK fibers.

Using a combination of horseradish peroxidase (HRP) histochemistry and immuno-beta-galactosidase staining, and pre-embedding immuno-electron microscopy, the present study was intended to re-examine the origins of enkephalin-like immunoreactivity (ENKI) in the rat lateral septum (LS), and to show the fine structures of septal ENKI fibers. Following HRP injection into the LS, double-labeled cells which contained a homogeneous blue reaction product of ENKI and a black or brown granular reaction product of retrogradely transported HRP were identified in 4 discrete brain regions: perifornical hypothalamic area at the level of the paraventricular nucleus (PeF); posterior part of the anterior hypothalamic nucleus (AHP); bed nucleus of the stria terminalis, medial division, posterolateral part (BSTMPL); and dorsal hypothalamic area (DA). Immuno-electron micrographs demonstrated that some of the ENKI terminals in the LS form synapses with the soma and dendrites of septal neurons devoid of ENKI, though ENKI dendrites postsynaptic to non-immunoreactive terminals were also seen in the LS. These findings suggest that a large proportion of septal ENKI fibers have their origins in the above regions (PeF, AHP, BSTMPL, DA) different from the previously considered one, and they further provide a morphological basis for the postsynaptic inhibitory effects of enkephalins on septal neurons.

Animals↗

PubMed1989

Lymphocyte subpopulations in high endothelial venules and lymphatic capillaries of bronchus-associated lymphoid tissue (BALT) in the rat.

The subpopulations of lymphocytes and non-lymphoid cells in high endothelial venules (HEV) and in lymphatic capillaries surrounding lymphoid follicles in bronchus-associated lymphoid tissue (BALT) were examined by electron microscopy after preembedding the tissue and staining with an immunoperoxidase technique. The results were compared with those obtained in gut-associated lymphoid tissue (GALT) reported previously. Monoclonal mouse-anti-rat T cell, IgG, IgM, IgA, and Ia antisera were used. Plasma cells that were reactive to anti-IgG, anti-IgM, and anti-IgA were detected as cells in which the 3',3'-diaminobenzidine tetrahydroxychloride reaction product was localized in rough endoplasmic reticulum and perinuclear spaces but not on plasma membranes. These plasma cells did not occur in either lymphatic capillaries or HEV in BALT as they did in GALT. Cells with surface Ig (sIg cells), T-cell antigen (T cells), and Ia antigen (Ia cells) were present in BALT. T cells were located predominantly in the follicular area opposite the bronchial epithelium; IgM- and IgG-reactive cells were found in the follicular area adjacent to the bronchial epithelium; and IgA-positive cells were found in the lateral part of the area where the T cells were localized (T-cell area). Ia cells were abundant throughout BALT and in moderate numbers in the epithelium. A striking observation was the presence of "nurse-cell"-like structures in the periphery of BALT. The percentages of T, sIgG, sIgM, and sIgA cells in the HEV were 54.7%, 2.4%, 28.9%, and 27.3%, respectively, and in the lymphatic capillaries, 41.2%, 3.8%, 38.2%, and 21.2%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Lymphatics and lymphoid tissue of the fallopian tube: immunoelectronmicroscopic study.

Lymphoid tissue of the human fallopian tube consists of follicles, lymphoepithelium, and lymphatic and blood capillaries and is located consistently in the interstitial part of the human fallopian tube. Using an immunoelectronmicroscopic technique, we have elucidated the ultrastructure of the lymphoid tissue of the human fallopian tube and the fine distribution and ultrastructure of the lymphatics associated with the rabbit fallopian tube. Lymphatic capillaries arise in the lamina propria mucosa and the periphery of follicles, where they are sparsely distributed, run through the muscular layer, and form a dense network in the subserosa. Characteristic features of the ultrastructure are aggregations of smooth muscle cells, alternating areas of densely and sparsely distributed collagen fibers, and unmyelinated nerve fibers beneath the lymphatic endothelium. Immunoelectronmicroscopic analysis has demonstrated an obvious difference in the distribution of T- and B-lymphocytes in the lymphoid tissue of the human fallopian tube. Many T-lymphocytes are present in the follicles and epithelium, but B-lymphocytes are either absent or rarely found. T-lymphocytes sometimes infiltrate into the basal lamina of the epithelium lying in close contact with the follicles. We conclude that the lymphoid tissue is constantly located in the interstitial part of the human fallopian tube and that intraepithelial lymphocytes, mainly T-lymphocytes, migrate via the basal lamina of the epithelium from follicles. Lymphatic capillaries in the fallopian tube may be the main migratory route of intraepithelial lymphocytes. The intraepithelial lymphocytes and epithelial cells of the fallopian tube have attracted considerable interest as a result of immunological studies of the recognition of spermatozoal antigens and the fertilized ovum.(ABSTRACT TRUNCATED AT 250 WORDS)

Fallopian Tubes↗

PubMed1989

An immuno-electron microscopic study on interactions among dendritic cells, macrophages and lymphocytes in the human palatine tonsil.

The sites of interaction between antigen-presenting cells (dendritic cells, macrophages) and lymphocytes in the human palatine tonsil were investigated by pre-embedding immuno-electron microscopy and acid-phosphatase histochemistry. Used in this study were: an S-100 protein antiserum recognizing Langerhans cells and interdigitating cells, OKT6 monoclonal antibody reacting with surface antigens of Langerhans cells, and Leu-3a monoclonal antibody directed to surface antigens of helper-T-cells. In the stratified squamous epithelium, Langerhans cells with characteristic rod-shaped or racket-shaped Birbeck granules exhibited S-100 protein and OKT6 immunoreactivites, and frequently extended long processes to adjacent lymphocytes. The subepithelial area contained a significant number of macrophages, some of which were closely apposed to interdigitating cells with S-100 protein immunoreactivity. Occasionally, macrophages with acid-phosphatase-positive phagosomes and/or lysosomes extended short processes to neighboring lymphocytes. In the interfollicular area, some interdigitating cells and a few Langerhans cells were seen in proximity to or in contact with lymphocytes stained with the Leu-3a antibody. These findings support previous in vitro studies suggesting the induction of T-cell activation by antigen-presenting cells. They further indicate that T-cell activation by the individual antigen-presenting cells takes place in different areas of the human palatine tonsil through a variety of cell-to-cell interactions.

Cell Communication↗