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Biomedical subjects

M Sakanaka

Publications and source records attributed to M Sakanaka.

At least 91 records · Page 5Linked to original sources

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↗

Development of tyrosine hydroxylase-like immunoreactive structures in the chick retina: three-dimensional analysis.

This study was designed to investigate the developmental profile of tyrosine hydroxylase-like immunoreactive structures in the chick retina in both frozen sections and wholemount preparations. In frozen sections, cells with tyrosine hydroxylase-like immunoreactivity were first detected in 10 to 15 cell rows from the innermost part of the inner nuclear layer on embryonic or incubation day 11. They were seen in the inner cell rows of the inner nuclear layer during later periods; by embryonic day 18, the immunoreactive cells were located 1 to 3 cell rows outward from the innermost part of the inner nuclear layer where mature immunoreactive cells mainly exist. The immunoreactive cells began to give rise to processes on embryonic day 13. The processes (possibly dendrites) gradually increased in number and intensity in sublayers 1 and 4 of the inner plexiform layer during prenatal life. Several days after hatching, an abrupt increase in immunoreactive processes was noted in sublayer 1 but not in sublayer 4. On the sixth postnatal day, retinal neural elements immunoreactive for tyrosine hydroxylase seemed to exhibit a distribution pattern similar to that of the adult chick. In wholemount retinas, immunoreactive cells were initially detected at the earliest stage of embryonic day 12 in a small circle termed "starting area" occupying the ventral part of the temporal retinal field. The closer to the "starting area," the earlier the retinal area began to express many immunoreactive cells. Thus tyrosine hydroxylase cell density in individual retinal areas, as represented by cell number per square millimeter, peaked in different developmental periods varying from embryonic day 12 to day 14. At this stage, immunoreactive cells were arranged irregularly in the retina. Thereafter, the cell density as well as total cell number gradually declined and reached a plateau around embryonic day 20 when tyrosine hydroxylase-like immunoreactive cells, like those in the mature retina, showed an even distribution throughout the retina.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

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↗

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↗

Histological examination of chick embryos with bilateral microphthalmus with reference to laterality in the visual apparatuses.

The histological abnormalities of chick embryos with bilateral microphthalmus were examined in serial paraffin sections with special reference to laterality in the visual apparatuses, including the cornea, lens, neural retina and pigment epithelium. There was marked laterality in the above structures; some eyeballs had individual, if incomplete, sublayers of the cornea and the neural retina, and others not. The sublayers of the neural retina were occasionally observed even in eyeballs at the stage of optic vesicle formation, in contrast to the previous notion that the pigment epithelium induces the maturation of the primordial neural retina after optic vesicle differentiation into the optic cup. There was also a case where developmental differences between the right and left eyeballs were absent except in the lens. These findings suggest that chick embryos with bilateral microphthalmus exhibit a more complex histological profile or diversity than previously considered, possibly as a result of the differential actions of various mutagens and endogenous trophic factors on the developing visual system.

Animals↗

Differential lectin binding on walls of thoraco-cervical blood vessels and lymphatics in rats.

Lectin binding in the walls of large to medium-sized blood vessels and lymphatics in the rat thoraco-cervical region was examined histochemically. The tunica intima of the aorta and superficial cervical artery showed positive reactions with wheat germ agglutinin (WGA) and Concanavalin A (ConA) but not with Dolichus biflorus agglutinin (DBA). The tunica media of the aorta exhibited intense WGA binding, especially on the smooth muscle cells, but the tunica media of the superficial cervical artery did not react with the lectin. Neither ConA nor DBA bound to the tunica media of the aorta and superficial cervical artery. The tunica adventitia of both arteries contained sites binding the three lectins, although DBA reactivity declined as the vascular diameter decreased. The tunica intima of the superior vena cava and azygos vein exhibited positive WGA and ConA binding, whereas DBA binding was noted on only part of the tunica intima of the superior vena cava and not on that of the azygos vein. The tunica media and tunica adventitia were reactive for all three lectins. The WGA and ConA binding sites in the tunica adventitia showed loose networks, suggesting lectin binding on connective tissue elements interlacing among smooth muscle bundles. Lectin binding sites in the walls of lymphatics exhibited an arrangement similar to those in the walls of the veins. Moreover valves protruding into the lumen showed intense WGA and ConA binding and scattered DBA binding. Three other lectins (Ulex europaeus agglutinin, peanut agglutinin, Maclura pomifera) were examined, but they showed no reactions with the vessels. Thus, the differential binding of lectins on the walls of blood vessels and lymphatics of various sizes suggests the functional complexity of monosaccharide residues in the vascular walls.

Animals↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

[Comparative evaluation of markers with reverse transcriptase inhibiting antibody in human immunodeficiency virus type 1 infection].

To investigate a non-RI test which is equivalent to the reverse transcriptase inhibiting antibody test, a reverse transcriptase inhibiting antibody was compared to the absolute number of CD-4 or CD-8 cells or CD-4/-8 ratio and also to photodensitometric analysis for western blotting. There is no correlation of the reverse transcriptase with any test for cell numbers and their ratio. In photodensitometry, relative units of anti-p65 and anti-p51 were compared with reverse transcriptase inhibiting antibody. The reverse transcriptase inhibiting antibody showed a higher correlation to the relative unit of p65 antibodies than that of p51 antibodies. The photodensitometric analysis of western blotting for a serum test may be a possible method to find a prognostic marker in HIV-1 infection.

Acquired Immunodeficiency Syndrome↗

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↗

Prostaglandin I2 synthase in the lymphatic endothelium of rat liver as revealed by preembedding immunoelectron microscopy.

Localization of prostaglandin I2 synthase-like immunoreactivity (PGI2SI) in the lymphatic endothelium of rat liver was investigated by means of preembedding immunoelectron microscopy. Vesicular and multivesicular bodies with PGI2SI were closely apposed to Golgi complexes of the endothelial cells. Membrane-bounded PGI2SI structures including vesicular and dense bodies were also present beneath the endothelial plasmalemma on both luminal and abluminal sides. Other organelles within the endothelial cells did not exhibit PGI2SI. These findings are consistent with previous biochemical and physiological studies suggesting prostaglandin I2 is produced in the Golgi apparatus and released into luminal and abluminal spaces through membrane-bounded structures containing PGI2SI.

Animals↗

[A case report of subdiaphragmatic pulmonary sequestration].

A 32-year-old man with extralobar pulmonary sequestration under diaphragm is reported. The patient was admitted because of abnormal shadow on chest X-ray film without any complaints. Chest roentgenogram showed a homogenous density at the left cardiophrenic angle. Aortogram demonstrated an abnormal artery arising from the abdominal aorta to left subphrenic mass shadow. On laparotomy a large cystic mass connected with diaphragm was found behind the stomach and removed successfully. The postoperative course was uneventful. The histological diagnosis was subphrenic pulmonary sequestration. The frequency, localisation, pathogenesis of pulmonary sequestration are discussed.

Adult↗

An immunoelectron microscopic study of von Willebrand factor in the thoracic duct endothelium of rats.

The localization of Von Willebrand factor-like immunoreactivity (VWFI) in the thoracic duct endothelium was investigated by means of preembedding immunoelectron microscopy. In the endothelial cells, VWFI was observed within rod-shaped Weibel-Palade bodies (WPBs) with an occasional tadpole-like appearance. The WPBs occasionally appeared to be associated with Golgi complexes of the endothelial cells. Some cisternae of the rough endoplasmic reticulum located in the perikarya of the endothelial cells also exhibited VWFI. There was a small number of large VWFI vesicles in the periphery of the endothelial cells. These findings provide morphological evidence for the thoracic duct as a site of VWF synthesis and suggest further that VWF is produced in the rough endoplasmic reticulum and transported into the WPBs and large vesicles occasionally via the Golgi apparatus.

Animals↗