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Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 73 records · Page 4Linked to original sources
PubMed1991

Ultrastructure of the red pulp in spleen innervation in horse and pig.

The innervation of the red pulp in the spleen of horse and pig was investigated by electron microscopy. In addition, the neurilemma was studied by immunohistochemistry specific for S-100 protein. In the pig, a large population of smooth-muscle cells extending from the smooth-muscle trabeculae was present in the red pulp. The cytoplasmic processes of reticular cells enwrapped the smooth-muscle cells, and nerve fibres were distributed between the smooth-muscle cells and the reticular cells. The nerve terminals clustered toward the facing of the smooth-muscle cells. Nerve fibres and terminals were not disclosed within the sheathed artery. Immunohistochemically the neurilemma showed a reaction positive for S-100 protein. In the horse, no smooth-muscle cells were noted in the red pulp. The nerve fibres terminated around the cytoplasmic processes of the reticular cells. Nerve fibres and terminals were disclosed within the sheathed artery, and the terminals contained both large and small dense-cored vesicles. Immunohistochemically the neurilemma showed a reaction negative for S-100 protein. These findings support the presence of the axon-bearing reticular cells described earlier in the horse spleen.

Animals↗
PubMed1991

Electron microscopy of histamine-induced contraction of the in vitro swine coronary artery.

Dose-dependent contractions of the in vitro swine coronary artery were induced by application of histamine and acetylcholine, but not of angiotensin II, ergonovine, noradrenaline, prostaglandin F2 alpha and serotonin. Ultrastructural changes especially of the tunica intima during the contractions were observed at 2, 5 and 30 min after application of histamine and acetylcholine. The intimal gutter spirally running along the longitudinal axis of the vessel was obscured, and the intimal surface became extensively indented. Exclusively in the histamine-treated samples, the increase in number and size of the intracellular vacuoles and the dilation of the intercellular clefts to the extent of the intercellular vacuoles were observed in the endothelium. Moreover, the enhancement of the endothelial permeability was indicated by the marker experiments using horseradish peroxidase. Such endothelial cell damages and the enhancement of the endothelial permeability may amplify the coronary artery contraction.

Acetylcholine↗
PubMed1991

Spectroscopic study on interaction of nucleic acid base with tryptophan-containing tripeptides: acetyl-Trp-X-Trp-NHCH3 (X = Gly, Asn, Asp, Gln and Glu).

As part of a series of peptides designed to have binding ability selective for each of the nucleic acid bases, five tripeptides consisting of N-acetyl-Trp-X-Trp-NHCH3 (X = Gly, Asn, Asp, Gln and Glu) were synthesized, and their abilities to form complexes with four different nucleotides were examined by the fluorescence and phase distribution methods. The association constants obtained indicated that, depending on the sort of X residue, the peptides showed a variation in their interaction with guanosine monophosphate (GMP), while no noticeable selectivity was observed for other nucleotides adenosine monophosphate (AMP), uridine monophosphate (UMP) and cytidine monophosphate (CMP). The binding mode of N-acetyl-Trp-Asp-Trp-NHCH3 for the guanine base was further investigated using the proton nuclear magnetic resonance (1H-NMR) method. The mode was suggested to involve intimate cooperation of (1) the hydrogen bond formation between the carboxyl group of the Asp side chain and the guanine C2-amino group, and (2) the stacking interaction of the base with two terminal Trp residues of the peptide. Such interaction was strengthened by the protonation of the guanine base. A tentative binding mode is proposed based on these results.

Molecular Structure↗
PubMed1991

Effects of dietary zinc deficiency on protein secretory functions of the mouse testis.

The effects of dietary zinc deficiency on testicular protein secretion, mainly that by Sertoli cells, were examined by electron microscopy and two-dimensional polyacrylamide gel electrophoresis of [35S] methionine-labeled secretory proteins from mouse testes. Zinc deficiency caused a significant decrease in the gonadosomatic index and a distinct increase in deoxyribonucleic acid concentration. Sertoli cells maintained normal fine-structural features; junctional complexes among Sertoli cells continued to divide seminiferous tubules into basal and adluminal compartments in the zinc-deficient mouse testes. Severe atrophic changes were observed in spermatogenic cells after meiotic division in the adluminal compartment, but not in spermatogonia located in the basal compartment. Zinc replacement treatment caused spermatogenesis to recover normally. Although total protein secretion was not affected by zinc deficiency, one polypeptide spot appeared due mainly to the loss of its target spermatogenic cells. The present study indicates that zinc is indispensable for spermatogenic cells after meiosis and that testicular protein secretory functions can be preserved in the absence of zinc.

Animals↗
PubMed1991

Utilization and metabolism of [U-14C]4' galactosyllactose (O-beta-D-galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)- D-glucopyranose) in rats.

O-beta-D-Galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl- (1----4)-D-glucopyranose (designated as 4'GL) are produced from lactose with Cryptococcus laurentii OKN-4. Excretion and metabolism of 4'GL in rats were examined using a radioisotope technique. [U-14c]4'GL was synthesized from [U-14C]lactose by Cryptococcus laurentii OKN-4. The 14CO2 in expired air was counted after oral administration of [U-14C]4'GL or [U-14C]lactose in conventional rats, rats treated with antibiotics and germ-free rats. The rate of 14CO2 excretion from conventional rats given [U-14C]4'GL was slower than that from those administered [U-14C]lactose. When [U-14C]4'GL was orally administered to rats given antibiotics, there was a 2-h delay in 14CO2 excretion, as compared to conventional rats. In germ-free rats, total excretion of 14CO2 from [U-14C]-4'GL decreased to about one-third of that of conventional rats during a 24-h period. Radioactivities in the serum, liver, and carcass of the [U-14C]4'GL oral administration group were lower than those of the [U-14C]lactose oral administration group. Radioactivities in the feces and urine however, were higher in [U-14C]4'GL group than in [U-14C]lactose group.

Animals↗
PubMed1991

Multiple opioid receptors and GTP-binding proteins.

We believed that GTP-binding protein (G-protein)-coupling receptor always transduces stimulatory signals to G-proteins. From our recent experiments using reconstitution techniques, however, it was revealed that some receptors transduce an inhibitory or no signal to G-proteins in specific tissues, despite some interaction between them. Here we discuss the molecular basis of mechanisms of such diverse modes of functional coupling between different subtypes of opioid receptors and G-proteins.

Animals↗
PubMed1991

[Kyotorphin like substance in human cerebrospinal fluid of patients with persistent pain].

Kyotorphin is an analgesic neuropeptide isolated from the bovine brain in 1979. Further studies showed that kyotorphin produces an analgesia through an increased release of met-enkephalin in the brain and the spinal cord. We showed that it is also found in the human cerebrospinal fluid and the concentrations of kyotorphin in normal human CSF is 1.19 +/- 0.51 pmol.ml-1. We also found that it is lower in patients with persistent pain (0.24 +/- 0.04 pmol.ml-1). Above results suggest that kyotorphin acts as a putative neuromediator and/or an endogenous pain modulator in the human brain.

Adult↗
PubMed1991

Cadmium toxicity on cultured neonatal rat hepatocytes: biochemical and ultrastructural analyses.

The effects of cadmium exposure on the protein secretory functions of cultured neonatal rat hepatocytes were analyzed by both two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and electron microscopy. [35S]Methionine-labelled protein secretion was significantly depressed by cadmium exposure in a dose-dependent manner (1, 10 and 100 microM). Protein secretory patterns resolved by 2D-PAGE and analyzed by autoradiography showed that besides albumin and transferrin, three polypeptide spots decreased their radiolabelling intensities, whereas four spots appeared due to cadmium exposure. Ultrastructural alterations in cultured neonatal rat hepatocytes induced by cadmium exposure were characterized by condensation of the nuclear chromatin, appearance of intra-nuclear inclusions, decrease in number of microvilli, increase in number of intra-mitochondrial granules and transformation of rough endoplasmic reticulum to cytoplasmic vesicles in a dose-dependent manner. Both biochemical and ultrastructural findings indicate that cadmium adversely affects the protein secretory functions of cultured neonatal rat hepatocytes.

Animals↗
PubMed1991

[5-fluorouracil concentration in gastroenterological tumor tissues, in adjacent normal tissues, and in serum after preoperative oral administration of 5'-deoxy-5-fluorouridine (5'-DFUR)].

The 5-fluorouracil (5-FU)-concentration in resected tumor tissues was compared with that in the adjacent normal tissues or that in serum. Twenty-three patients with cancer of the digestive organs [(carcinoma of the stomach (12), colon (6), gallbladder (1), liver (1), ampulla of Vater (1), bile duct (1) and pancreas (1)] were administered orally 600-1, 200 mg/day of 5'-deoxy-5-fluorouridine (5'-DFUR) for 3 to 5 consecutive preoperative days. The average 5-FU-concentration in tumor tissues of 14 patients with 16 specimens measured 5 hours after final administration of 5'-DFUR was 62 ng/g. This level was significantly higher than that in adjacent normal tissues (21 ng/g, p less than 0.01). With 10 out of these 14 patients, the 5-FU-concentration in the serum was also measured. Among these 10 patients, the concentration of 5-FU in tumors (54 ng/g) was significantly higher than in adjacent normal tissues (19 ng/g) and in serum (12 ng/ml). At 6 to 9 hours after final administration, the mean concentration of 5-FU was 33 ng/g (n = 4) in tumor tissues, 30 ng/g (n = 5) in adjacent normal tissues and 24 ng/ml in serum. There was no significant difference among these mean values. For 4 patients whose specimens were taken at 17 to 18 hours after the last 5-FU administration, the mean concentration of 5-FU was 29 ng/g (n = 4) in tumor tissues, 14 ng/g (n = 3) in adjacent normal tissues and 4 ng/ml (n = 2) in serum.

Administration, Oral↗
PubMed1991

[Thallium-201 lung uptake in patients with chronic phase of myocardial infarction].

To study pathophysiological significance of Tl-201 lung uptake in coronary artery disease Tl-201 lung uptake was studied in 159 patients with chronic phase of myocardial infarction. Tl-201 lung uptake images were collected after rest Tl-201 myocardial imaging. Tl-201 lung uptake was estimated by comparing maximal lung counts with maximal myocardial counts (thallium lung heart ratio: LHR). Good correlation between LHR and mean pulmonary artery wedge pressure (mPw) and between LHR and left ventricular ejection fraction (EF) were obtained, (mPw = 2.7 +/- 10.5 LHR r = 0.52 n = 102, p less than 0.001, EF = 84.9-52.2 LHR r = -0.61 n = 159, p less than 0.001). It was noted that Tl-201 did not accumulate uniformly through the lung field and usually maximal Tl-201 lung uptake was noted at the basal zone of the right lung. Tl-201 lung uptake in the upper zone of the right lung increased in proportion to the hemodynamic deterioration. Interesting differences were noted between Tl-201 lung uptake in patients with chronic phase of myocardial infarction and that in patients with acute phase of myocardial infarction. The prognosis and clinical status of patients with markedly increased Tl-201 lung uptake (LHR greater than 0.8) in chronic phase were more excellent than the patients with similar Tl-201 lung uptake in acute phase. Hemodynamic parameters in patients with markedly increased Tl-201 lung uptake (LHR greater than or equal to 0.8) in chronic phase were significantly better than in those in acute phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1991

A limitation of endoscopic ultrasound: an unusual case of early gastric cancer overlying a pancreatic rest.

Endoscopic ultrasonography (EUS) has been developed as a valuable tool for examining the depth of carcinoma invasion and evaluating the submucosal tumors of the gastrointestinal tract. In the present case, that of a 60-yr-old woman, the work-up of radiography and conventional endoscopy revealed an ulcerating cancer of the stomach. Subsequent EUS showed a solid high-echoic mass occupying the third (submucosal) and fourth (muscularis propria) layers of gastric wall, suggestive of an advanced cancer invading the muscularis propria. However, histologic examination of the surgical specimen showed that this tumor was early submucosal carcinoma confined to the surface of a pancreatic rest. Retrospective evaluation of EUS pictures proved that the mass had tubular or circular echoless structures associated with thickening of the fourth layer, suggesting the pancreatic rest. Our experience in reviewing EUS findings of this tumor seems noteworthy, inasmuch as EUS indicates that EUS may provide certain characteristic features of gastric pancreatic rest that should be differentiated from invading carcinoma.

Carcinoma↗
PubMed1990

Identification and purification of a Bombyx mori homologue of FTZ-F1.

Extracts from embryos and from posterior and middle silk glands of the silkworm, Bombyx mori contain a sequence specific DNA binding factor termed BmFTZ-F1. The factor binds to the recognition site of FTZ-F1, a positive regulator of the fushi tarazu gene in Drosophila melanogaster. BmFTZ-F1 and FTZ-F1 share the same methylation interference patterns, the same chromatographic behaviors and similar protease digestion profiles. Anti-FTZ-F1 cross reacts with BmFTZ-F1. These results indicate that BmFTZ-F1 is a B. mori homologue of FTZ-F1. The mobility of the factor-DNA complex formed in the silk gland extract changes depending on the developmental stages. Purification of BmFTZF1 to an almost homogeneous state reveals that the factor is a 73 kd protein.

Animals↗
PubMed1990

'Ischemic tolerance' phenomenon found in the brain.

We investigated the possibility that neuronal cells given a mild ischemic treatment sufficient to perturb the cellular metabolism acquired tolerance to a subsequent, and what would be lethal, ischemic stress in vivo. Cerebral ischemia was produced in the gerbils by occlusion of both common carotids for 5 min, which consistently resulted in delayed neuronal death in the CA1 region of the hippocampus. Minor 2-min ischemia in this model depletes high-energy phosphate compounds and perturbs the protein synthesis, but never causes neuronal necrosis, and therefore was chosen as mild ischemic treatment. Single 2-min ischemia 1 day or 2 days before 5 min ischemia exhibited only partial protective effects against delayed neuronal death. However, two 2-min ischemic treatments at 1 day intervals 2 days before 5 min ischemia exhibited drastically complete protection against neuronal death. The duration and intervals of ischemic treatment, enough to perturb cellular metabolism and cause protein synthesis, were needed respectively, because neither 1-min ischemia nor 2-min ischemia received twice at short intervals exhibited protective effects. This 'ischemic tolerance' phenomenon induced by ischemic stress--which is unquestionably important--and frequent stress in clinical medicine, is intriguing and may open a new approach to investigate the pathophysiology of ischemic neuronal damage.

Animals↗
PubMed1990

Medullary carcinoma with lymphocytic infiltration of the stomach. Clinicopathologic study of 27 cases and immunohistochemical analysis of the subpopulations of infiltrating lymphocytes in the tumor.

The current study attempts to clarify the possible immune response that occurs in medullary carcinoma with lymphocytic infiltration of the stomach by an immunohistochemical analysis of the subpopulations of tumor-infiltrating lymphocytes. This carcinoma was histologically characterized by the sparse population of small nests consisting of poorly differentiated carcinoma cells, widely separated by intervening nondesmoplastic stroma infiltrated uniformly with abundant lymphocytes frequently accompanied by lymph follicles. An immunohistochemical analysis revealed that T-cells were evenly distributed throughout the tumor with intimate contact with individual carcinoma cells, except the lymph follicles consisted mainly of B-cells. Because of the similarities of morphologic features and subpopulations of tumor-infiltrating lymphocytes of this carcinoma to the normal lymphoid tissue, an organized immune response combined with cell-mediated and humoral immunities against the invading carcinoma cells seemed to occur in this type of gastric carcinoma, resulting in a excellent prognosis compared with that in ordinary gastric carcinoma.

Adult↗
PubMed1990

Evidence for receptor-mediated inhibition of intrinsic activity of GTP-binding protein, Gi1 and Gi2, but not G0 in reconstitution experiments.

The receptor-mediated inhibition of intrinsic activities of GTP-binding proteins (G-proteins) was studied. Pertussis toxin (IAP)-substrate G-protein, Gi1, Gi2 or G0, was prelabeled with [alpha-32P]GDP and reconstituted with synaptic membranes of the guinea pig cerebellum in the presence of 0.02% of Chaps. Intrinsic activities of G-proteins were evaluated by the release of [alpha-32P]GDP in exchange for added GppNHp or GDP in reconstituted preparations. U-50,488H (1 nM-10 microM), a specific kappa-subtype of opioid receptor agonist, inhibited the [alpha-32P]GDP release in exchange for added 1 microM GppNHp in Gi1-reconstituted preparations in a concentration-dependent manner. On the other hand, the kappa-opioid agonist at 10 microM increases the Km values of GppNHp, but not GDP in exchange for [alpha-32P]GDP release in preparations reconstituted with Gi1 or Gi2, but not with G0. These findings indicate that kappa-opioid receptor is coupled to inhibition of intrinsic activities of Gi1 and Gi2, but not G0, in guinea pig cerebellar membranes. In addition, it was revealed that the mode of action is mediated by a decrease in affinity of GTP (or its analog) for G proteins, but not by a change in affinity of GDP.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1990

Phosphorylated mu-opioid receptor purified from rat brains lacks functional coupling with Gi1, a GTP-binding protein in reconstituted lipid vesicles.

The effects of phosphorylation of a mu-opioid receptor on signal transduction to G-protein were studied. The mu-opioid receptor purified from rat whole brains was reconstituted with purified Gi1 in phosphatidylcholine vesicles. DAGO, a mu-opioid agonist at 1 microM-1 mM increased GTPase activity by 10-110% of control, in a concentration-dependent manner. When the mu-opioid receptor was phosphorylated by cyclic AMP-dependent protein kinase prior to reconstitution with Gi1, the DAGO-stimulation was markedly reduced (20% increase at 1 mM DAGO).

Animals↗