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Biomedical subjects

S Ueno

Publications and source records attributed to S Ueno.

At least 235 records · Page 13Linked to original sources
PubMed1994

Immunohistochemical investigation of epidermal growth factor receptor expression in ameloblastomas.

Immunohistochemical analysis was performed to determine the localization of epidermal growth factor receptor (EGFR) in ameloblastomas. Ameloblastoma samples were classified into follicular, plexiform, and basal cell types. The number of cases in each category was 17, 19 and 3, respectively. Ameloblastomas, disregarding their histological type, consist of two cell forms: peripheral columnar cells and central stellate cells. The frequency of EGFR expression was much higher in the latter than in the former (P < 0.005). On analysis with respect to histological types, the frequency of EGFR expression in columnar cells was not significantly different between the follicular and the plexiform types, but was observed more frequently in the stellate cells in the follicular than in the plexiform ameloblastomas (P < 0.05). This pattern of EGFR expression was not consistent with the PCNA staining pattern, but was similar to that of keratin expression which we have reported previously. The present study suggests that EGFR expression in ameloblastomas is closely associated with tumour differentiation, and squamous differentiation in particular.

Ameloblastoma↗
PubMed1994

The strategy to treat disseminated neuroblastoma utilizing bone marrow transplantation: what is the surgeon's role?

The current role of surgery was evaluated in seven consecutive patients with high-risk neuroblastoma (six stage 4 patients and one stage 3, abdominal origin, and all over 12 months of age at diagnosis) treated with new modalities utilizing bone marrow transplantation (BMT). In six of these seven patients, a grossly complete excision of the primary tumor was achieved, and four have survived for 133, 69, 39, and 28 months with no further evidence of disease. The remaining patient with celiac neuroblastoma only underwent a biopsy during a second-look laparotomy after chemoradiotherapy, and thereafter developed local and distant recurrences and ultimately succumbed to the tumor. The timing of surgical intervention varied, either before or after chemotherapy, and did not appear to affect the ultimate survival. Although surgical excision of the primary tumor remains a very high priority in the overall treatment scheme, the most important factor remains the eradication of the tumor by well-planned courses of intensive chemotherapy (e.g., A1 Protocol of the Study Group of Japan). Thus, after having induced complete remission, for consolidation, it is necessary to kill all remaining tumor cells by giving supralethal doses of chemotherapy including total body irradiation (TBI) assisted by BMT.

Adrenal Gland Neoplasms↗
PubMed1994

Comparison of hepatotoxicity caused by mono-, di- and tributyltin compounds in mice.

The in vivo induction of hepatotoxicity, as evaluated by the activity of ornithine carbamyl transferase in serum, was investigated in mice administered orally with the following three butyltin compounds: tributyltin chloride (TBTC), dibutyltin dichloride (DBTC) and monobutyltin trichloride (MBTC). The minimal concentrations of TBTC and DBTC that caused hepatotoxicity at 24 h after oral administration were 180 mumol and 60 mumol/kg, respectively, while MBTC did not induce liver injury even at 7000 mumol/kg. Additionally, when the administered doses were equivalent (180 mumol/kg), a time course (3-96 h) study revealed that the hepatotoxicity of TBTC and DBTC appeared at 24 and 12 h, respectively, but that MBTC showed no hepatotoxicity even at 96 h. The amounts of Sn excreted into urine for 4 days were 1.5 fold greater with TBTC than with DBTC treatment and were lowest in MBTC group. Similarly, the total liver Sn content was 2- to 5-fold greater in the TBTC group than in the DBTC group whereas the liver Sn content in the MBTC treatment showed the lowest value throughout the 3- to 96-h period. Thus, the non-hepatotoxicity of MBTC may be due either to low absorption through the digestive tract of mice or to the low levels of Sn in liver; however, the level of Sn in liver was not associated with the induction of hepatotoxicity by TBTC and DBTC.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Structural features of myelin basic protein mRNAs influence their translational efficiencies.

The myelin basic protein (MBP) gene expresses several alternatively spliced products with the same 5' and 3' untranslated regions (UTRs). It has been reported that its expression may be regulated not only at the transcriptional level but also at the translational level during development. We engineered several MBP mRNA deletion mutants with 5' (-48, -37, -27, -22, and -10) and 3' UTRs of differing lengths and examined the translational efficiencies of these constructs in cell-free systems. The translational efficiencies of the constructs differed significantly over a range of almost 10-fold. A deletion of 11 nucleotides from the 5' end of the natural (i.e., -48) MBP mRNA resulted in an approximate fourfold reduction in translational efficiency. Further truncation of the 5' UTR increased the translational efficiencies of the constructs as has been observed with many RNAs. These results suggest that there may be a positive control element between -48 and -37 nucleotides in the 5' UTR of MBP mRNA. The effects of modifying the lengths of the 5' UTR on the translational efficiency of mRNAs encoding the 21.5-kDa and 14-kDa MBPs were the same, suggesting that the effect observed was not unique to the 21.5-kDa MBP mRNA. Truncating the 3' UTR of four different alternatively spliced MBP mRNAs also altered their translational efficiencies. Thus, the 5' and 3' UTRs of MBP mRNAs appear to influence the translation of these mRNAs, and such factors may be involved in the translational regulation of MBP gene expression.

Animals↗
PubMed1994

Effective method for discriminating between oral bacterial and human alkaline phosphatase activity.

Alkaline phosphatase (ALPase) activity was quantitatively compared in various kinds of oral bacteria. High ALPase activity was detected in 3 species of periodontal bacteria, Porphyromonas gingivalis, Prevotella intermedia and Capnocytophaga sputigena. The ALPase activity detected in these bacteria was almost completely inhibited in the presence of 1% sodium dodecyl sulfate (SDS). By contrast, the activity of mammalian ALPase isoenzymes was not inhibited at all even in the presence of 1% SDS. These results indicate that the ALPase assay in combination with 1% SDS can identify the origin of ALPase detected in gingival crevicular fluid as being from bacteria or from a host response. Clinical examination with adult periodontitis revealed that ALPase activity in gingival crevicular fluid from the patients consisted of a combination of SDS-sensitive and SDS-resistant activities. These findings indicate that ALPase activity detected in gingival crevicular fluid originates not only from bacteria but also from a host response.

Adult↗
PubMed1994

Idiopathic AA amyloidosis manifested by autonomic neuropathy, vestibulocochleopathy, and lattice corneal dystrophy.

A 69-year-old Japanese woman with non-familial amyloidosis had polyneuropathy and profound autonomic neuropathy, and kappa chain monoclonal gammopathy. Immunohistopathological examination showed protein AA and protein AP in the amyloid deposits. She showed involvement of the vestibulocochlear nerve and lattice dystrophy of the cornea. Vestibulocochleopathy and corneal lattice dystrophy have been reported in familial amyloid polyneuropathy type IV, Finnish type, but never in non-familial amyloidosis.

Aged↗
PubMed1994

Preparation and characterization of liposomes incorporating hydrophobic poly(amino acid)s with different secondary structure.

Incorporation of hydrophobic poly(amino acid) into liposomal membranes was achieved by the polymerization of N-carboxy anhydrides of amino acids in the egg yolk phosphatidylcholine (EyPC) bilayer under reduced pressure at 30 degrees C. The trapped volumes for the liposomes with and without polypeptides were 8.1-10.3 l mol-1 and 11.4 l mol-1, respectively. The permeability barrier abilities of liposomal membranes were lowered by the incorporation of polypeptides into the membrane bilayers. Water permeation across the membrane bilayer was more effective for the liposome with the alpha-helical polypeptide than for that with the beta-sheeted one.

Diffusion↗
PubMed1994

Protective effects of thiol compounds on chromate-induced toxicity in vitro and in vivo.

The effects of thiol compounds (L-cysteine ethyl ester, 2,3-dimercaptosuccinic acid, or 2,3-dimercapto-1-propanesulfonic acid) on the toxicity induced by chromate (potassium dichromate) were investigated in HeLa cells and mice. Chromate-induced cytotoxicity evaluated by inhibition of cell growth and chromium content of the cells was diminished by all of the thiol compounds tested when the cells were incubated in the medium with both chromate and one of the thiol compounds. In mice injected ip with a thiol compound immediately after injection of chromate, mortality, ornithine carbamyl transferase activity in the serum, and chromium content in the liver were diminished remarkably compared with mice injected with chromate alone. These thiol compounds also caused an increase of urinary chromium excretion. These results suggest that the thiol compounds tested are useful for treating chromate-induced toxicity when they are given immediately after intake of the metal.

Animals↗
PubMed1994

[Detection of mycobacterial DNA by in vitro enzymatic amplification in lung nodular lesions in a patient with ovarian immature teratoma].

We experienced a 13-year-old girl with ovarian immature teratoma, who presented multiple pulmonary nodular lesions. Thoracotomy was performed to rule out the metastatic tumor. Histopathological study of the resected tumor suggested a possible diagnosis of tuberculosis. However, neither the acid-fast staining nor the mycobacterial culture of the specimens confirmed the diagnosis. Polymerase chain reaction (PCR) and hybridization technique successfully detected specific DNA sequence for M. tuberculosis from the specimens. The lesions regressed after anti-mycobacterial therapy. Detecting mycobacterial DNA by PCR, which led to a proper diagnosis and treatment of this patient, is a rapid and sensitive method in diagnosis of tuberculosis. This method is recommended to distinguish tuberculosis from neoplastic lesions of the lung, where surgical intervention is necessary.

Adolescent↗
PubMed1994

[An experimental study on the correlation between hepatic hemodynamics and ultrastructural and immunohistochemical changes in sinusoidal endothelial cells after major hepatectomy].

The correlation between hepatic hemodynamics and changes of sinusoidal endothelial cells after major hepatectomy was studied using adult mongrel dogs. The sinusoidal endothelial cells were examined both ultrastructurally and immunohistochemically. Three types of hepatectomy, i.e., 30%, 70% and 84% resection, were applied to these animals, 16 each. The results obtained were as follows: 1) Portal vein pressure and the vascular resistance after operation were significantly higher in 70% hepatectomized dogs than those in 30% hepatectomized dogs. Twenty-four hours later, however, the difference was not significant. 2) Portal vein pressure and the vascular resistance after operation were much higher in 84% hepatectomized dogs than those in 30% and 70% hepatectomized dogs. Only 2 of 84% hepatectomized dogs survived more than 8 hours, and the two dogs also died of circulatory insufficiency 24 hours postoperatively. 3) Electron microscopic observation revealed that the sinusoidal endothelial fenestrae in 70% hepatectomized dogs were contracted 3 hours after operation but dilated 24 hours postoperatively. These changes in 70% hepatectomized dogs correlated well with hepatic hemodynamics. 4) Immunohistochemical observation using thrombomodulin staining method indicated that the sinusoidal endothelial cells in 84% hepatectomized dogs were seriously damaged 3 hours after operation.

Animals↗
PubMed1993

Molecular cloning of a novel putative G protein-coupled receptor (GPCR21) which is expressed predominantly in mouse central nervous system.

A novel cDNA clone encoding a putative G protein-coupled receptor (named GPCR21) was isolated from a mouse brain cDNA library along with its homologue, GPCR01 (the mouse counterpart of previously reported rat receptor R334 [(1991) FEBS Lett. 292, 243-248]) by the polymerase chain reaction using degenerate oligonucleotide primers. Northern blotting and reverse transcription-polymerase chain reaction analyses showed predominant expression of these two receptors in the central nervous system. In situ hybridization analysis revealed their prominent expression in the limbic system and further demonstrated the differential distribution of their mRNAs in mouse brain. Although the ligands for these receptors are yet to be identified, the significant sequence homology between these receptors suggests that they constitute a new receptor subfamily and they possibly represent different receptor subtypes for an unknown neurotransmitter.

Amino Acid Sequence↗
PubMed1993

Expression of the D3 dopamine receptor gene and a novel variant transcript generated by alternative splicing in human peripheral blood lymphocytes.

The sequential reverse transcription and polymerase chain reaction amplified the mRNA coding for the D3 dopamine receptor (D3R) in human peripheral blood lymphocytes. Pharmacological analysis confirmed the binding of the D3R specific ligand to the lymphocytes. In addition, there was a novel shorter variant transcript of the D3R gene generated by alternative splicing in lymphocytes and brain. This variant, termed D3(TM4-del), has a 143 bp deletion and encodes a 138 amino acid protein containing the first three transmembrane domains of the native D3R.

Adult↗
PubMed1993

Nicotinic acetylcholine receptor in dissociated rat nucleus tractus solitarii neurons.

The ACh-activated response of the acutely dissociated neuron from the rat nucleus tractus solitarii (NTS) was investigated using conventional and perforated-patch techniques. In the present preparation, ACh and nicotine evoked inward transient currents in approximately 30% of NTS neurons tested. The ACh-activated inward current reversed the direction near 0 mV and was inhibited by D-tubocurarine in a dose-dependent manner. In contrast, muscarine resulted in no detectable changes in the NTS neurons. Some populations of the NTS had nicotinic but no muscarinic acetylcholine receptors.

Acetylcholine↗
PubMed1993

Heterotopic pancreas as a rare cause of gastrointestinal hemorrhage in the newborn: report of a case.

We report herein a female infant in whom a heterotopic pancreas in the stomach caused gastrointestinal hemorrhage during the newborn period. Endoscopy was essential for ruling out other causes of hemorrhage and to follow the patient until the time of elective surgery at 6 months of age. Heterotopic pancreas should be borne in mind as a rare cause of gastrointestinal hemorrhage in the newborn when an unexplained gastrointestinal hemorrhage continues, and the lesion was discussed in relation to our experience of upper gastrointestinal endoscopies and a review of the literature.

Choristoma↗
PubMed1993

A kindred of hereditary adult-onset leukodystrophy with sparing of the optic radiations.

We describe a family with hereditary adult-onset leukodystrophy with sparing of the optic radiations, shown clinically, neuroradiologically and electrophysiologically. All five affected members developed their leukodystrophy in their fourth decade and clinical features steadily progressed. The sparing of the optic radiations is not typical of other leukodystrophies. We suggest that this is a new clinical entity.

Adult↗
PubMed1993

Spontaneous synaptic transmission in dissociated Meynert neurons with the attached synaptic boutons.

1. Neurons acutely dissociated from the nucleus basalis of Meynert of adult rats showed spontaneous currents with rapid onset and slow decay under the whole-cell patch-clamp recording. 2. The current had the reversal potential close to the theoretical Cl- equilibrium potential (ECl) and was suppressed by 2 x 10(-6) M bicuculline and 3 x 10(-6) M strychnine. 3. The spontaneous current was suppressed reversibly in the Ca(2+)-free solution containing either EGTA or BAPTA (5 mM). The enhancement of the frequency and amplitude of the current was observed with elevated extracellular K+ concentration, which was also suppressed in the presence of the Ca(2+)-free solution. 4. Nicardipine, a blocker of voltage-dependent Ca2+ channels, had an inhibitory effect as well. 5. A selective GABAB agonist, baclofen, blocked the spontaneous current, whereas a selective antagonist, phaclofen, potently enhanced the current. 6. It is concluded that the observed spontaneous current was a spontaneous inhibitory postsynaptic current (IPSC) due to the release of GABA from the attached synaptic boutons. The release was suppressed by a GABAB receptor activation, indicating that the GABAB receptor regulates the release of GABA from nerve terminals and acts as a negative autoreceptor.

Animals↗