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Biomedical subjects

T Shin

Publications and source records attributed to T Shin.

At least 127 records · Page 7Linked to original sources
PubMed1992

Neurite regeneration in the cat recurrent laryngeal nerve: an immunohistochemical study.

The recurrent laryngeal nerve (RLN) consists of various motor, sensory and autonomic nerve fibers, although it has not been established whether different neuronal types exhibit a similar ability to regenerate. To address this question, freezing was used to injure the cat RLN fibers and the presence or absence of immunoreactivity for neuropeptides or transmitter-synthesizing enzymes was then examined as a marker to classify the fibers. In the control RLN, calcitonin gene-related peptide-immunoreactive (CGRP-IR) fibers were the highest in number and were distributed throughout the nerve fascicles. The number of substance P-immunoreactive (SP-IR) fibers was about 40% that of CGRP-IR fibers, while a portion of CGRP-IR fibers was found to contain SP immunoreactivity. Relatively low numbers of tyrosine hydroxylase-immunoreactive (TH-IR) and neuropeptide Y (NPY-IR) nerve fibers were seen which tended to form clusters. The distribution pattern of NPY-IR fibers was very similar to that of TH-IR fibers. In the regenerating RLN 1 week after the freezing injury, the fastest growing axons were CGRP-IR, while the regenerating rates of SP-IR, TH-IR and NPY-IR fibers were slower than that of CGRP-IR fibers. These results suggest that the ability for neurite regeneration varies among neuron types and that CGRP-IR fibers possess the most rapid ability to regenerate.

Animals↗
PubMed1992

One-stage operation for synchronous primary cancers of the lung and the trachea.

A rare combination of synchronous primary adenocarcinoma of the right upper lobe of the lung and adenoid cystic carcinoma of the subglottic trachea was simultaneously managed by lobectomy with lymph node dissection and sleeve resection of the upper trachea through median sternotomy and cervical collar incisions. This combined approach should be a perfectly acceptable one for synchronous tumors of the proximal trachea and of the right upper and middle lobes and left upper lobe of the lung.

Adenocarcinoma↗
PubMed1992

Immunohistochemical study of intralaryngeal ganglia in the cat.

To study the mechanism of autonomic regulation in the larynx, intralaryngeal local ganglia of the cat were investigated using immunohistochemical techniques. Small intralaryngeal ganglia were found in the peripheral portions of internal branches of the superior laryngeal nerve. Ninety-one percent of the ganglionic neurons were immunoreactive (IR) to vasoactive intestinal polypeptide (VIP), and 10% of the VIP-IR cells were also immunoreactive to enkephalin (ENK) and/or substance P (SP). The immunoreactivity of neuronal cell bodies remained unchanged even after denervation of the bilateral superior and recurrent laryngeal nerves. A dense distribution of calcitonin gene-related peptide (CGRP)-IR nerve fibers was found around almost all neuronal cells in the intralaryngeal ganglia. A few VIP-IR, ENK-IR, and SP-IR nerve fibers were also observed. Only the CGRP-IR fibers disappeared after the denervation experiments. In the laryngeal glands and mucosal arterioles, VIP-IR nerve terminals were found that were also immunoreactive to ENK and/or SP. However, these immunoreactive nerve endings in the glands and arterioles remained after the denervation experiments. The results of our study indicate that laryngeal exocrine secretion and blood flow are regulated by postganglionic autonomic parasympathetic fibers from intralaryngeal ganglia that contain VIP alone or VIP with ENK and/or SP, and that these ganglionic neurons may be innervated by CGRP-IR extrinsic nerve fibers.

Animals↗
PubMed1992

Intracordal injection increases glottic closing force in recurrent laryngeal nerve paralysis.

Glottic closing pressure during swallowing was measured in the cat with a catheter pressure transducer to study the effectiveness of intracordal injection in increasing glottic pressure in unilateral recurrent laryngeal nerve paralysis. Swallows were elicited by pouring water into the pharynx while the animal was under light anesthesia with ketamine. Peak pressure of the glottic closure for the control group during deglutition was 68.0 +/- 10.5 mm Hg (mean +/- standard deviation). Peak pressure decreased to 22.0 +/- 3.6 mm Hg just after sectioning of the unilateral recurrent laryngeal nerve, and rose to 39.8 +/- 8.3 mm Hg by silicon injection into the paralyzed vocal fold. In a study of chronic cases 1 month or more after unilateral recurrent laryngeal nerve section, peak pressure was 49.1 +/- 23.4 mm Hg, and varied widely from 21 to 92 mm Hg because of differences in the position of the paralyzed vocal fold and the degree of compensation by the unaffected vocal fold. In the group that had the paralyzed vocal fold fixed in the median position, peak pressure was almost the same as that of the control group. When the paralyzed vocal fold was fixed in either the paramedian or lateral position, peak pressure was 33.3 +/- 7.0 mm Hg. This value was significantly elevated to 45.8 +/- 10.4 mm Hg by injection of silicon, though it remained lower than that of the control. These results suggest that the decrease in glottic closing force during swallowing as a result of unilateral recurrent laryngeal nerve lesion is compensated for by the unaffected vocal fold to some degree and is improved by intracordal injection.

Acute Disease↗
PubMed1992

Study on the mechanism of an experimental immunological intrahepatic cholestasis model.

Tuberculin-sensitized guinea pigs were intravenously injected with heat-killed Propionibacterium acnes followed by an intravenous injection of purified protein derivatives 7 day later, resulting in the induction of intrahepatic cholestasis. Using this experimental model, the following results were obtained: (1) Both uptake and release of bile acid were inhibited in the hepatocytes prepared from the cholestasis guinea pigs. (2) The results of the erythritol clearance method indicated that the decrease in bile flow observed in the cholestasis guinea pigs was mostly attributable to the reduced bile excretion from the canaliculi. (3) The decrease in the formation of bile acid independent bile flow was the cause of the decrease in bile flow observed in the cholestasis guinea pigs. (4) There was no change in the permeability of the interhepatocellular tight junction in the cholestasis guinea pigs.

Animals↗
PubMed1991

Stimulation of endothelial secretion of tissue-type plasminogen activator by repetitive stretch.

Endothelial cells (EC) synthesize many of the fibrinolytic components and anticoagulants present in plasma. EC have been demonstrated to release tissue type plasminogen activator (t-PA) and its rapid inhibitor type 1 plasminogen activator inhibitor (PAI-1). In vivo, EC lining a blood vessel are exposed to the forces of the circulation, predominantly shear stress and pulsatile stretch. We have previously reported that repetitive stretch of EC in culture will stimulate prostacyclin secretion. In this study, the effects of cyclic stretch on the production of t-PA and PAI-1 by cultured EC were examined. EC harvested from human saphenous vein were seeded in culture plates with flexible membrane bottoms and grown to confluence. Vacuum (-20 kPa) was used to deform the membrane bottoms to 24% maximum strain. EC in the experimental group were subjected to 24% maximum strain at 60 cycles/min (0.5 sec elongation alternating with 0.5 sec relaxation), while control EC were grown on the same membranes but kept stationary in the same incubator. After 1, 3, and 5 days, the cell numbers were counted and the media were collected and analyzed for t-PA and PAI-1 by ELISA. The result shows a significant increase in t-PA production with the cyclic stretch on Days 3 and 5. There was no significant difference in PAI-1 levels in stretched versus stationary EC. We concluded that cyclic stretch of EC in vitro can selectively stimulate t-PA production and may account for the relative nonthrombogenicity of the endothelium in vivo.

Cells, Cultured↗
PubMed1991

Target-specific projections of intrinsic ganglionic neurons with different chemical codes in the canine larynx.

The distribution and origin of peptide-containing intrinsic nerve fibers within the larynx were examined by immunohistochemistry and denervation experiments in the dog. In the normal larynx, a dense network of vasoactive intestinal polypeptide (VIP)-immunoreactive (IR) fibers was seen around the acini of submucosal glands. VIP-, substance P (SP)-, or calcitonin gene-related peptide (CGRP)-IR fibers were seen in the walls of submucosal arteries, and VIP-, neuropeptide Y (NPY)-, or enkephalin (ENK)-IR fibers were seen around the arteries in the muscle tissue. Most of these peptide-IR fibers remained after bilateral denervation of the superior and inferior laryngeal nerves. Several small intrinsic ganglia were found along the peripheral branches of the laryngeal nerves. About 97% of the ganglionic neurons were VIP-IR; of these, 44% were immunoreactive to VIP alone, 22% to VIP and NPY, 13% to VIP and SP, 7% to VIP and ENK, and 14% to VIP, NPY and SP. These results reveal that the exocrine glands and blood vessels are innervated by the intrinsic ganglionic neurons and that subpopulations of ganglionic neurons with different chemical codes innervate specific target organs in the canine larynx.

Animals↗
PubMed1991

Effect of gomisin A in an immunologically-induced acute hepatic failure model.

Guinea pigs were sensitized with trinitrophenylated liver macromolecular protein fraction (TNP-LP1) prepared by using sodium trinitrobenzenesulfonate of strong immunogenicity as the hapten and LP1 as the carrier protein. The administration of trinitrophenylated hepatocytes and lipopolysaccharide to these TNP-LP1-sensitized guinea pigs through the mesenteric vein 2 weeks later resulted in the induction of acute hepatic failure accompanied by massive hepatic cell necrosis in almost all of the guinea pigs. Using this experimental model, the effect of Gomisin A on the induction of immunological acute hepatic failure was examined. As a result, the administration of gomisin A remarkably improved the survival rate and serum transaminase levels of the immunologically-induced acute hepatic failure guinea pigs. Gomisin A also improved the histological changes of the liver in these guinea pigs. These results suggested that gomisin A is effective for the improvement of immunologically-induced acute hepatic failure in our experimental model.

Animals↗
PubMed1991

Purification and some properties of a thermostable metal proteinase produced by Thermomicrobium sp. KN-22 strain.

An extreme thermophile that produces a heat-stable proteinase was isolated from hot-spring water and classified as Thermomicrobium sp. KN-22 (growth temperature, 50-83 degrees C; and optimum growth temperature, 70 degrees C). The proteinase was purified from the culture broth of this strain by fractionation with ammonium sulfate, chromatography on columns of DEAE-cellulose and CM-Sepharose CL-6B, and HPLC on TSKgel CM-5PW. The purified enzyme gave a single band on SDS-polyacrylamide gel electrophoresis and a single peak after HPLC (yield 8.8%). The enzyme had maximum activity at pH 8.5 and at 75 degrees C and it was stable up to 60 degrees C. The molecular weight of the enzyme was 35,000 by SDS-PAGE. Since the enzymatic activity was completely inhibited by EDTA, o-phenanthroline, and phosphoramidon, it appears that the enzyme is a metal proteinase.

Amino Acid Sequence↗
PubMed1991

Effect of cyclic stretch on endothelial cells from different vascular beds.

Endothelial cells (EC) mediate many of the organ responses to shock. Much of our knowledge of EC are obtained from cell culture studies. However, compared to the dynamic milieu in vivo, the stationary environment for large-vessel EC may be artificial and inappropriate. In this study, the morphology, growth rate, and production of prostacyclin (PGI2) by EC obtained from different vascular beds under stationary and dynamic conditions were examined. EC were harvested from the thoracic aorta (Ao), pulmonary artery (PA), and vena cava (VC) of the same calves and exposed to 0.5 sec 24% deformation alternating with 0.5 sec relaxation (i.e., 60 cycles/min). Our results show that in response to the cyclic regimen, VCEC were elongated perpendicular to the force vector and their actin filaments aligned in the same direction, while AoEC and PAEC did not exhibit any morphological changes. The growth rate of AoEC (but not PAEC or VCEC) was significantly enhanced when stimulated by cyclic stretch. In addition, AoEC demonstrated an increased PGI2 synthetic activity with cyclic stretch, while PAEC and VCEC were unaltered. We conclude that the maintenance of EC phenotype and function is dependent on the hemodynamic milieu in vivo and may be influenced by the vascular origin of the cultured EC.

Animals↗
PubMed1990

Interferon gamma stimulates prostaglandin E2 production by mouse Kupffer cells.

When mononuclear phagocytes, including Kupffer cells, are activated by various agents, they synthesize and release arachidonic acid metabolites, prostaglandins (PGs) and leukotrienes (LTs). In this study, we examined the effect of in vitro Kupffer cell activation with recombinant murine IFN gamma on PGE2 and LTB4 secretion. IFN gamma enhanced PGE2 secretion, and this effect of IFN gamma was stronger than that of IL-1 or TNF. Moreover, IFN gamma promoted LTB4 release especially in the absence of PGs. On the other hand, dexamethasone and indomethacin inhibited and, EGTA and TMB-8, which reduce intracellular Ca++ Levels, blocked IFN gamma induced PGE2 production, which suggested that the activation of phospholipase A2 and cyclooxygenase in Kupffer cells requires the elevation of intracellular Ca++ levels.

Animals↗
PubMed1990

Synthesis of eicosanoids by Propionibacterium acnes-elicited liver adherent cells and their effect on production of interleukin 1 and tumor necrosis factor.

When heat-killed Propionibacterium acnes (P. acnes) is intravenously injected into rats or mice, liver adherent cells including macrophages and Kupffer cells increase in number and they synthesize various kinds of biologically-active materials. We studied the production of eicosanoids and the cytokines, interleukin 1 (IL-1) and tumor necrosis factor (TNF), by P. acnes-elicited liver adherent cells and the regulatory mechanisms of eicosanoids in the synthesis of cytokines. As a result, P. acnes-elicited liver adherent cells synthesized not only prostaglandin (PG) E2, 6-keto-PGF1 alpha, thromboxane B2 and leukotriene B4, but also IL-1 and TNF. In addition, PGE2 and PGI2 suppressed the production of these cytokines. These results suggested that there are auto-regulatory mechanisms in production of cytokines in the liver.

Animals↗
PubMed1990

Distribution of neuropeptide-like immunoreactive nerve fibers in the canine larynx.

The distribution of neuropeptide immunoreactive nerve fibers in the canine larynx was examined. In the epithelium of supra- and subglottic regions, a dense distribution of substance P (SP)- and calcitonin gene-related polypeptide (CGRP)-immunoreactive (IR) nerve fibers was observed. Some vasoactive intestinal polypeptide (VIP)-IR intraepithelial nerve fibers were also seen in the subglottic region. In the laryngeal glands, a dense distribution of VIP-IR nerve fibers with a few SP- and enkephalin (ENK)-IR nerve fibers were found around the acini. In the walls of arteries in the lamina propria, many VIP-, SP-, and CGRP-IR nerve fibers were seen, whereas neuropeptide Y-, ENK-, and VIP-IR nerve fibers were predominantly distributed around the arteries in the vocal muscle. In the free edge of the vocal cord, few immunoreactive nerve fibers were detected within the epithelium and around the arteries in the lamina propria. These results suggest that there are regional differences in the occurrence of peptides in nerve fibers innervating the epithelium and the blood vessels in the larynx and that the perception mechanism of the epithelium and the regulatory system of local blood flow are varied according to their location in the larynx.

Animals↗
PubMed1990

[Observations on the effects of Nd-YAG laser irradiation in the canine tongue].

Recently, the Nd-YAG laser has been widely applied for head and neck surgery. This medical instrument provides several advantages, including hemostatic efficacy and cutting capability which are dependent on manipulation. The purpose of this study is to discuss the clinical application of Nd-YAG laser in the field of oropharyngeal surgery. For this reason, the canine tongue is used in this study. After irradiation by Nd-YAG laser, observations were performed on histological findings, measurement of tissue temperature and changes in blood vessels. The results obtained are as follows: 1) Irreversible tissue changes were found in the center of the irradiated area, with other tissue degeneration occurring in the surrounding areas. 2) Within the coagulated degenerative area, blood vessels were completely embolized. 3) Temperature measurements revealed that there were minimal effects on the surrounding tissues. 4) The coagulated degenerative area was replaced by granulation tissue subsequently occurring after wound healing. 5) The Nd-YAG laser was useful for oral and paranasal surgery, because these diseases are localized in the cavity. 6) Non-contact type Nd-YAG laser was indicated for vaporization of the lesions and was particularly useful for vaporizing superficial benign lesions. In this case, close range, low power vaporization is recommended. Conversely, vaporization for hemangioma and/or malignant lesions were most effective with high power irradiation. 7) Contact type Nd-YAG laser might be suitable for cutting and excision of lesions, but careful attention must be given determining the safety margin for application in malignant lesions, because tissue degeneration when using contact type Nd-YAG laser is less reactive than in non-contact type.

Animals↗
PubMed1990

[Surgical repair of total anomalous pulmonary venous connection in neonates and infants--prevention for pulmonary venous obstruction at the site of anastomosis].

From October, 1980, to June, 1987, thirty-eight infants less than one year old underwent correction for total anomalous pulmonary venous connection (TAPVC). Overall operative mortality and late mortality were 13% and 6%, respectively. Residual pulmonary hypertension was noted in 4 patients: three had pulmonary venous obstruction at the site of atrial anastomosis (PVOA) and one had supracardiac (Ia) lesion left after repair of mixed type (IV: Ia + III) of TAPVC. Two late deaths occurred in these with PVOA. Twenty-two patients with supracardiac (I) or infracardiac (III) TAPVC were divided into three groups according to the technical development in atrial anastomosis: the large anastomosis in which venous incision reached into at least one pulmonary vein beyond common pulmonary vein and the continuous running suture were used in 10 patients (group 1), the appropriate size of anastomosis in which venous incision limited within the common pulmonary vein and the continuous running suture used in 4 patients (group 2), and the appropriate size of anastomosis and the interrupted suture in 8 patients (group 3). PVOA were 3 (33%) in group 1, but 0 (0%) in group 2 and 3. Two late death occurred all in group 1 with PVOA. Cardiopulmonary bypass time and aortic clamp time in group 3 were 91 min and 74 min respectively, which did not become longer than those in both group 1 and group 2. Interrupted suture technique does not make operating time longer than continuous running suture one. PVOA is one of the important factors predicting late operative result.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1990

The enhancement of liver injury by lipopolysaccharide in an experimental drug-induced allergic hepatitis model.

When guinea pigs sensitized with trinitrophenylated (TNPed) liver protein 1 (LP1) were intravenously injected with TNPed isolated hepatocytes, remarkable hepatic cell injury was induced 24 hours later. In this experimental model, drug-induced allergic liver injury was induced by using trinitrobenzen sulfonic acid (TNBS) as the hapten and LP1 as the carrier. When these sensitized guinea pigs were intravenously injected with 10 micrograms of lipopolysaccharide (LPS) along with TNPed isolated hepatocytes, serum AST and ALT levels were remarkably higher than those of the guinea pigs not injected with LPS. Hepatic cell necrosis was also more extensive, and some bleeding was observed. Although none of the guinea pigs died even after 24 hours, when 50 micrograms of LPS was injected, many of the guinea pigs started to die and the survival rate was 5% at 24 hours. These results suggested that LPS enhanced liver injury in this experimental drug-induced allergic liver injury model.

Animals↗