Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 505 records · Page 28Linked to original sources

PubMed1994

Non-effective dose of exogenously applied L-dopa itself stereoselectively potentiates postsynaptic D2 receptor-mediated locomotor activities of conscious rats.

We attempted to clarify whether or not under inhibition of central dopa decarboxylase non-effective i.p. doses of L-dopa potentiate D2 receptor-mediated locomotor activities without conversion to dopamine in normal and i.v.t. 6-hydroxydopamine-treated rats. In normal rats, only the highest dose of quinpirole, a selective D2 agonist, at ranges used (0.01-1 mg/kg, s.c.) slightly increased the total counts of locomotor activities for 140 min after injection. A simultaneously injected non-effective dose of L-DOPA (30 mg/kg) potentiated locomotor activities by quinpirole (0.1 and 1 mg/kg). L-dopa potentiated quinpirole (1 mg/kg)-induced locomotor activities 90 to 140 min after the injection with marked increase in basal release of L-DOPA without increase in dopamine release simultaneously monitored during striatal microdialysis, compared to quinpirole alone. D-dopa (30 mg/kg) produced no potentiation. In 6-hydroxydopamine-treated rats, a non-effective dose of L-dopa (10 mg/kg) also potentiated quinpirole (0.3 mg/kg)-induced locomotor activities. L-dopa acting on a recognition site for itself stereoselectively potentiates postsynaptic D2 receptor-mediated locomotor activities of rats.

Animals↗

PubMed1994

Endogenously released L-dopa itself tonically functions to potentiate postsynaptic D2 receptor-mediated locomotor activities of conscious rats.

A non-effective dose of exogenously applied L-dopa itself stereoselectively potentiates postsynaptic D2 receptor-mediated locomotor activities of rats. We further attempted to clarify whether or not endogenously released L-dopa tonically functions to potentiate activities of these receptors, simultaneously monitoring locomotor activities and basal release of L-dopa and dopamine during striatal microdialysis in conscious rats. Quinpirole (1 mg/kg, s.c.) alone, a selective D2 agonist, increased locomotor activities and decreased basal L-dopa and dopamine release 20-140 min after injection. Pretreatment with alpha-methyl-p-tyrosine (3 mg/kg, i.p.), a tyrosine hydroxylase inhibitor, decreased locomotor activities and further decreased L-dopa release without modification of dopamine release, compared to quinpirole alone, whereas 3-hydroxybenzylhydrazine (100 mg/kg, i.p.), a central dopa decarboxylase inhibitor, further increased locomotor activities and markedly increased L-dopa release without modification of dopamine release. Endogenously released L-dopa itself functions tonically to potentiate activities of postsynaptic D2 receptors relevant to locomotor movement of rats.

Animals↗

PubMed1994

Ultrastructural demonstration of salmon-type gonadotropin-releasing hormone (sGnRH) in the olfactory system of masu salmon (Oncorhynchus masou).

Immunocytochemical and immunoelectron microscopic localization of salmon-type gonadotropin-releasing hormone (sGnRH) were observed in the olfactory system (olfactory epithelium, olfactory nerve and olfactory bulb) of masu salmon (Oncorhynchus masou) to investigate its possible involvement in the olfactory functions. sGnRH-immunoreactive (ir) bipolar neuron, which might be related to the terminal nerve, was located in dorsal portion of the olfactory nerve. sGnRH-ir gold particles were concentrated on electron-dense granule-like structures of 50 nm in diameter in fibers of the olfactory nerve close both to the olfactory epithelium and to the olfactory bulb. These findings suggest that sGnRH might participate in neurotransmission and/or neuromodulation in the olfactory system of masu salmon. sGnRH would become a useful molecular marker for studying the olfactory imprinting and homing mechanisms in salmonids.

Animals↗

PubMed1994

Intermittent expression of BmFTZ-F1, a member of the nuclear hormone receptor superfamily during development of the silkworm Bombyx mori.

BmFTZ-F1 is a sequence-specific DNA-binding factor in the silkworm Bombyx mori sharing similar biochemical characteristics with Drosophila FTZ-F1, a member of the nuclear hormone receptor superfamily. Using DNA sequence homology with FTZ-F1 and information on tryptic peptide sequences of BmFTZ-F1, we isolated a cDNA encoding for BmFTZ-F1. Amino acid sequences in the zinc finger DNA-binding region and the putative ligand-binding domain of BmFTZ-F1 showed strong similarity to not only FTZ-F1 but also its mammalian homologues, LRH-1, ELP, and Ad4BP, suggesting the importance of each region for the function of these proteins. Northern blot analyses of RNA isolated from the middle and posterior silk glands and fat bodies showed that a 6.1-kb BmFTZ-F1 mRNA is present in all tissues so far examined. Expression of BmFTZ-F1 mRNA is intermittent, being high during larval molting and both the larval-pupal and the pupal-adult transformations. Injection of 20-hydroxyecdysone at the third day of the 5th instar larvae induced BmFTZ-F1 mRNA in the posterior silk gland after 24 hr. When 5th instar silk glands were cultured in vitro, BmFTZ-F1 mRNA was induced by a 6-hr exposure to 20-hydroxyecdysone followed by 6 hr in hormone-free medium. These results suggest that BmFTZ-F1 is inducible by decline in the ecdysteroid titer and may play an important role in the development of the silkworm as a transcription factor.

Amino Acid Sequence↗

PubMed1994

Growth rate suppression of cultured mammalian cells enhances protein productivity.

Suppression of proliferation of cells which contain stable or stabilized mRNA coded for a protein to be produced, a partial mimic of cell differentiation, was examined for enhancing protein production by cultured mammalian cells. Hybridoma 2E3 cells which were adapted to be interleukin-6 sensitivity growth-suppressed accumulated the mRNA of IgG1 which is reported stable, and IgG1 production rate increased as a result when their growth was suppressed with interleukin-6. A myeloma cell line was similarly adapted; the obtained myeloma cells can be used as host cells for enhancing production of exogenous proteins by suppressing growth with interleukin-6. Temperature-sensitively growth-suppressible mutants of mouse mammary carcinoma FM3A were transfected with cDNA of IgM lambda 1 chain and cultured at nonpermissive temperature to enhance production of lambda 1. Addition of various growth-suppressive reagents to culture medium was studied for finding methods suitable for suppressing growth while maintaining high cell viability. Caffeine yielded the best results among these reagents. Deprivation of various growth-supporting components in culture medium was also tested; simultaneous deprivation of insulin and transferrin viably suppressed growth of hybridoma 2E3 cells, resulting in enhanced antibody productivity.

Animals↗

PubMed1994

Lysophosphoinositide-specific phospholipase C in rat brain synaptic plasma membranes.

A membrane preparation from rat brain catalyzed the hydrolysis of [2-3H]glycerol-labeled lysophosphatidylinositol (lysoPI) to yield monoacylglycerol (MG) and inositolphosphates. This phospholipase C activity had an optimal pH of 8.2. The membrane preparation did not require the addition of Ca2+ for its maximum activity, but the activity was inhibited by addition of 0.1 mM EDTA to the assay mixture and was restored by simultaneous addition of 0.2 mM Ca2+. The activity was found to be localized in synaptic plasma membranes prepared by Ficoll and Percoll density gradients. The phospholipase C was highly specific for lysoPI; diacylglycerol formation from phosphatidylinositol, and MG formation from lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylserine were below 5% of that observed with lysoPI under the conditions used. We concluded that there is a pathway for phosphatidylinositol metabolism in brain synaptic membranes which is different from the well-characterized phosphoinositide-specific phospholipase C pathway.

Animals↗

PubMed1994

Activation of tumor-infiltrating macrophages by a synthetic lipid A analog (ONO-4007) and its implication in antitumor effects.

ONO-4007 is a novel synthetic analog of lipid A subunit and has been shown to exert antitumor activities on various experimental tumors with less toxicity than lipopolysaccharide. It remains unclear, however, what biological activities of this compound are relevant to its antitumor effects. We therefore investigated the activation of macrophages by ONO-4007 in vitro and in vivo and its implication in antitumor effects, using mouse MM46 mammary tumor as an experimental model. Intravenous injection of ONO-4007 produced significant therapeutic effects on this solid tumor. ONO-4007 could stimulate glycogen-elicited peritoneal macrophages in vitro, not only to produce tumor necrosis factor (TNF), but also to exert cytocidal activities against MM46 cells in vitro. Substantial TNF production was induced in tumor tissue by i. v. injection of ONO-4007, and its successive administration to tumor-bearing mice gave tumor-infiltrating macrophages a prominent in vitro tumoricidal activity and primed them for in vitro TNF secretion. These results suggest that activation of tumor-infiltrating macrophages to a direct tumoricidal state as well as to TNF secretion in tumor tissues may be at least some of the antitumor effects of this novel lipid A analog.

Animals↗

PubMed1994

A case of choledochal cyst associated with adenocarcinoma exhibiting sarcomatous features.

One complication of choledochal cyst in adulthood is the development of secondary carcinoma, usually well-differentiated adenocarcinoma. We report a case of extrahepatic bile duct carcinoma associated with choledochal cyst and presenting predominantly sarcomatous features. The patient was a 52-year-old female who presented with abdominal fullness and pain. Ultrasound (US), computed tomography (CT), and cholangiography revealed a choledochal cyst with a tumor. The resected choledochal cyst was 10 x 7.5 cm and contained a protruding, ulcerated tumor, measuring about 4.0 x 2.5 cm. Histologically, the tumor was composed of spindle-shaped or fusiform cells with occasional pleomorphic or bizarre giant cells and abundant fibrous stroma, similar to malignant mesenchymal tumors. However, further histologic and immunohistochemical examination revealed that the tumor was adenocarcinoma with prominent sarcomatous features. To our knowledge, sarcomatous change in extrahepatic bile duct carcinoma associated with choledochal cyst has not been previously described.

Adenocarcinoma↗

PubMed1994

Surgical treatment of lung cancer in the octogenarian.

The purpose of this study was to investigate the value of surgical treatment for lung cancer in the octogenarian. Thirty-three patients 80 years of age or older (mean age, 82.4; range, 80 to 92 years; 25 men, 8 women) underwent surgical resection in our units between 1974 and 1991. The operative mortality rate was 3%, and the 5-year survival rate was 32%. The relative 5-year survival rate (survival rate of our subjects/that of matched population) was 61%. The mortality and long-term survival rates were similar to those in younger patients. In this study, long-term survival had no significant dependence on stage of disease, histologic tumor type, or complete versus incomplete resection. It was dependent mainly on postoperative complications, in particular, cardiorespiratory complications (cardiac complications, p = 0.0005; respiratory complications, p < 0.05). These data suggest that the octogenarian who suffers from lung cancer deserves the opportunity for a cure and the long-term benefits of surgical treatment, on the condition that no postoperative major cardiorespiratory complications set in.

Aged↗

PubMed1994

Open heart operation in a young child with spherocytosis.

Open heart operations on patients with hereditary spherocytosis have been reported rarely. Young children who have not yet undergone splenectomy have a high risk of intraoperative hemolysis because of the heart-lung machine and secondary renal failure. We report the case of a 15-month-old child with spherocytosis who underwent an open heart operation without serious complications as a result of careful and appropriate perioperative management.

Ductus Arteriosus, Patent↗

PubMed1994

Absence of association of TAP and LMP genes with type 1 (insulin-dependent) diabetes mellitus.

Although one of the major genes which cause type 1 (insulin-dependent) diabetes mellitus is located in the class II HLA region in humans, its precise location is still unknown. In order to investigate whether TAP (Transporter associated with Antigen Processing) and LMP (Low Molecular Weight Polypeptide) genes, which are located in the class II HLA region, are HLA-linked diabetogenic genes, the association of TAP1, TAP2 and LMP2 genes with type 1 diabetes was analyzed in the Japanese population. No difference in allele frequencies of these genes was detected between diabetic patients and control subjects. On the other hand, DQA1 and DQB1 genes showed significant association with type 1 diabetes. These data suggest that the diabetogenic gene in the class II HLA region may be located near the DQA1 and DQB1 loci, rather than the TAP and LMP loci.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

Role of beta-adrenoceptors in the expression of morphine withdrawal signs.

The effects of intracerebroventricular (i.c.v.) pretreatment with the noradrenergic neurotoxin DSP-4 and beta 1- and beta 2-adrenoceptor antagonists on the expression of morphine withdrawal signs were investigated in mice. Mice were chronically treated with morphine (8-45 mg/kg, s.c.). Several withdrawal signs were observed following naloxone challenge in morphine-dependent mice which had been pretreated with vehicle. Treatment with DSP-4 before the naloxone challenge suppressed the expression of morphine withdrawal signs, including jumping and "wet dog" shakes. Similarly, pretreatment with the beta 1-antagonist atenolol significantly reduced the incidence of naloxone-precipitated jumping and "wet dog" shakes. However, pretreatment with the beta 2-antagonist ICI118,551 suppressed the expression of "wet dog" shakes, but not that of jumping. These findings suggest that the central noradrenergic system may mediate the expression of withdrawal signs. The blocking effects of beta-antagonists indicate that naloxone-precipitated jumping may be mediated predominantly by beta 1-adrenoceptors, while naloxone-precipitated "wet dog" shakes may be mediated by both beta 1- and beta 2-adrenoceptors.

Adrenergic Agents↗

PubMed1994

Evidence for a dopamine receptor subtype sensitive to combination of D1 with D2 antagonist in measurement of G-protein activity using rat striatal membranes.

In rat striatal membranes, various kinds of dopamine receptor agonists stimulated low-Km GTPase activity in a concentration-dependent manner. This stimulation by bromocriptine, pergolide and apomorphine was partially inhibited by sulpiride (SUL), a D2-selective antagonist, markedly inhibited by combination of SUL with SCH 23390 (SCH), a D1-selective antagonist, and not modified by SCH alone. The stimulation by BAM-1110 was resistant to SUL or SCH alone but abolished by combination of SUL with SCH. These findings suggest the presence of another subtype of a dopamine receptor in a functional in vitro bioassay system in rat striata.

Animals↗

PubMed1994

Disturbance of autoregulation in patients with ruptured intracranial aneurysms: mechanism of cortical and motor dysfunction.

Serial measurements of local cerebral blood flow were obtained with inhalation of stable xenon and computed tomography prior to and during induced hypertension with continuous infusion of dopamine (7-15 micrograms/kg/min) in 34 patients who underwent surgery for treatment of subarachnoid hemorrhage due to ruptured intracranial aneurysm. Cerebral vasospasm was detected angiographically in all but one of the patients studied. Vasospasm was not symptomatic in 19 patients, but was in the other 15 patients. Disturbance of autoregulation was observed just after surgical operation. In the latter group, local cerebral blood flow in the territory of the middle cerebral artery and the corona radiata on the craniotomy side reached their lowest values, 25.1 +/- 6.8 mL/100 g/min and 15.7 +/- 1.8 mL/100 g/min, respectively, on days 10-14, and each subsequently increased significantly, to 34.3 +/- 7.3 mL/100 g/min and 19.9 +/- 2.0 mL/100 g/min, respectively, during induced hypertension. In conclusion, cortical dysfunction and motor palsy in the patients studied here were thought to be due to significant reduction in local cerebral blood flow in the cortical territories of the middle cerebral artery and corona radiata, respectively.

Adult↗

PubMed1994

Early-onset type 2 (non-insulin-dependent) diabetes mellitus is associated with glucokinase locus, but not with adenosine deaminase locus, in the Japanese population.

To investigate the possible contribution of glucokinase (GCK) and adenosine deaminase (ADA) loci to the genetic susceptibility to type 2 (non-insulin-dependent) diabetes mellitus, we studied the association of these loci with type 2 diabetes in the Japanese population. Fifty patients with type 2 diabetes and 50 control subjects were analyzed for microsatellite polymorphism 3' to the GCK gene and PstI polymorphism in the ADA gene by polymerase chain reaction. The frequency of the most common GCK allele (Z) was significantly lower in type 2 diabetic patients than that in control subjects and a longer Z + 2 allele was more common in type 2 diabetic patients (26% vs. 15%, P = 0.053), particularly in those with younger age of onset (33% vs. 15%, younger onset type 2 diabetes vs. control, P = 0.014). The frequency of genotypes containing at least one Z + 2 allele was significantly more common in type 2 diabetic patients (46% vs. 28%, P < 0.05), particularly in those with younger age of onset (61% vs. 28%, relative risk 4.00, P < 0.01). In contrast, there was no difference in allelic or genotypic frequencies of PstI polymorphism in the ADA gene between the two groups. Despite the association between the GCK locus and type 2 diabetes, none of the patients had known mutations (Glu265-->AM265, Glu279-->AM279, Gly299-->Arg299, Glu300-->Gln300, Leu309-->Pro309). These results suggest that the GCK locus, but not the ADA locus, contributes to the genetic susceptibility to type 2 diabetes in Japanese.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Deaminase↗

PubMed1994

Effect of mixed live vaccine (Newcastle disease and infectious bronchitis) and Mycoplasma gallisepticum on the chicken respiratory tract and on Escherichia coli infection.

Interaction between mixed live vaccine (Newcastle disease and infectious bronchitis), Mycoplasma gallisepticum (MG) and Escherichia coli (EC) was studied in specific-pathogen-free chickens, aged 7 days, inoculated intranasally. In the tracheas of chickens inoculated with vaccine, MG and EC, profuse multiplication of EC occurred together with severe and persisent histological lesions, and some birds died from EC infection. Similar though less dramatic effects occurred in birds that received vaccine and EC. The tracheas of chickens inoculated with the vaccine alone, or with MG and EC, or with MG alone, showed comparatively mild effects. There were no histological lesions in the tracheas of chickens inoculated with EC alone. This study suggests that the field use of mixed live vaccine in flocks infected with MG may induce EC septicaemia.

Animals↗

PubMed1994

Metabolic and biosynthetic alterations in cultured astrocytes exposed to hypoxia/reoxygenation.

To investigate the astrocyte response to hypoxia/reoxygenation, as a model relevant to the pathogenesis of ischemic injury, cultured rat astrocytes were exposed to hypoxia. On restoration of astrocytes to normoxia, there was a dramatic increase in protein synthesis within 3 h, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of metabolically labeled astrocyte lysates showed multiple induced bands on fluorograms. Levels of cellular ATP declined during the first 3 h of reoxygenation and the concentration of AMP increased to approximately 3.6 nmol/mg of protein within 1 h of reoxygenation. Reoxygenated astrocytes generated oxygen free radicals early after replacement into ambient air, and addition of diphenyliodonium, an NADPH oxidase inhibitor, diminished the generation of free radicals as well as the induction of several bands on fluorogram. Although addition of cycloheximide on reoxygenation resulted in inhibition of both astrocyte protein synthesis and accumulation of cellular AMP, it caused cell death within 6 h, suggesting the importance of protein synthesis in adaptation of hypoxic astrocytes to reoxygenation. Potential physiologic significance of biosynthetic products of astrocytes in hypoxia/reoxygenation was suggested by the recovery of glutamate uptake. These results indicate that the astrocyte response to hypoxia/reoxygenation includes generation of oxygen free radicals and de novo synthesis of products that influence cell viability and function in ischemia.

Adenosine Monophosphate↗

PubMed1994

Olfactory responses of chum salmon to amino acids are independent of large differences in salt concentrations between fresh and sea water.

In chum salmon captured at the coastal sea and the natal river, the magnitudes of the olfactory nerve responses to the amino acids after perfusion of the olfactory epithelium with artificial pond water (APW) were similar to those after perfusion with artificial sea water (ASW), although the concentrations of Na+, Cl- and Ca2+ in ASW were 986, 430 and 27 times higher than those in APW, respectively. The findings suggest that the permeability of these ions across the apical membranes of olfactory cells do not essentially contribute to the transduction mechanism in the salmon.

Amino Acids↗