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Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 145 records · Page 8Linked to original sources
PubMed2000

Immunoglobulin G and M hepatitis C virus core antibody (JCC.2) response in chimpanzees infected experimentally with hepatitis C virus.

OBJECTIVE: To evaluate changes in serum immunoglobulin M (IgM) and G (IgG) hepatitis C virus (HCV) core antibodies after HCV infection in acute hepatitis C. METHODS: Serum HCV RNA and IgM and IgG HCV core antibodies were investigated using sera sequentially sampled from three chimpanzees experimentally infected with HCV. Serum IgG HCV core antibody titer was measured using a JCC.2 enzyme-linked immunosorbent assay (ELISA) kit (Chemo-Sera-Therapeutic Research Center, Kumamoto, Japan). IgM core antibody titer was measured using horseradish peroxidase-labeled monoclonal anti-human IgM as the secondary antibody for the JCC.2 ELISA kit. Serum HCV RNA was detected using the 5' noncoding region as the primer according to the reverse transcriptase (RT) nested polymerase chain reaction (PCR) and competitive RT-PCR method. RESULTS: IgM JCC.2 antibody was detected when alanine aminotransferase (ALT) peaked, showing the closest correlation with the changes in ALT. A period during which IgM JCC.2 antibody was positive but HCV RNA as determined by RT-nested PCR was negative was observed after the elevation of ALT level. CONCLUSION: These results indicate the usefulness of detection of serum IgM JCC.2 antibody in making a definitive diagnosis of acute hepatitis C and the follow-up observation of hepatitis C.

Acute Disease↗
PubMed2000

Localization of EMSP1 expression during tooth formation and cloning of mouse cDNA.

Enamel matrix serine proteinase 1 (EMSP1) is a proteolytic enzyme that has been isolated from the developing enamel of pig teeth. Its apparent function is to degrade the organic matrix in preparation for enamel maturation. The expression of EMSP1 has never been investigated in another organism besides the pig, and EMSP1 expression in the enamel organ has never been specifically demonstrated in ameloblasts. Here we report the expression of recombinant pig EMSP 1 (rpEMSP 1), the generation of rabbit polyclonal antibodies against rpEMSP1, the characterization of the antibodies and EMSP1 expression by Western blot and immunohistochemical analyses, the cloning and characterization of a full-length cDNA encoding mouse EMSP1, and the localization of EMSP1 expression in ameloblasts in mouse day 14 first and second molars by in situ hybridization. The full-length mouse EMSP1 cDNA clone has 1,237 nucleotides, excluding the poly(A+) tail, and encodes a preproprotein of 255 amino acids. Mouse EMSP1 shares 75% amino acid identity with pig EMSP1 and has three potential N-linked glycosylation sites, two of which are conserved in the pig homologue. Western blot analysis shows that the polyclonal antibodies are specific for EMSP1 and do not cross-react with trypsin. Immunohistochemistry of pig incisors shows discrete staining in the surface enamel at the earliest part of the maturation stage. In mouse molars, in situ hybridization gives a distinct and specific signal in maturation-stage ameloblasts, and in the junctional epithelium following tooth eruption. We conclude that EMSP1 is expressed by pig and mouse ameloblasts during the early maturation stage of amelogenesis.

Amino Acid Sequence↗
PubMed2000

Immunohistochemical detection and distribution of enamelysin (MMP-20) in human odontogenic tumors.

Enamelysin is a tooth-specific protease that was initially isolated from porcine enamel organ and subsequently from human odontoblasts. Since this protease is thought to play important roles in tooth development, the evaluation of enamelysin in odontogenic tumors may aid our understanding of the histogenesis and cell differentiation of such lesions. A monoclonal antibody (203-1C7) was generated against synthesized human enamelysin oligopeptide and was used to assess the immunolocalization of enamelysin in healthy developing tooth germs and various types of odontogenic lesions. In tooth germs, enamelysin expression was detected only in the secretory enamel. Thus, 203-1C7 may serve as an enamel-specific marker in the late stage of enamel matrix development and calcification. In odontogenic lesions, strong enamelysin staining was demonstrated in the immature enamel matrix of ameloblastic fibro-odontomas and odontomas. Furthermore, enamelysin was also detected in globular amyloid masses and calcified foci in calcifying epithelial odontogenic tumors, hyaline droplets, small and large mineralized areas in adenomatoid odontogenic tumors, and a portion of ghost cells in calcifying odontogenic cysts. Positive reactivity was also observed in selected tumor cells in some of these tumors. No intracellular staining for enamelysin was detected in ameloblastomas or the ameloblastic portion of ameloblastic fibro-odontomas. Also, enamelysin was not detected in dentin, dysplastic dentinoid hyaline matrices, and cementum that were present within the tumors examined. Thus, taken together, our results suggest that the enamelysin-specific monoclonal antibody (203-1C7) may be utilized as a marker of early enamel development and that enamelysin may be involved in the pathogenesis of specific odontogenic tumors.

Ameloblastoma↗
PubMed2000

Preparation and characterization of acrylic hydrogels neutralized by basic amino acids.

Basic amino acids were used as neutralizers in the gellation of Eudispert as an acrylic hydrogel. Arginine and lysine successfully neutralized Eudispert, as did sodium hydroxide, and formed hydrogels. A gentle rise of pH was observed as the dosage of the base increased when arginine and lysine were used, in contrast to the sharp rise of pH observed when sodium hydroxide was used. The rank of viscosity of the prepared hydrogels was as follows: lysine > arginine > NaOH. The release rate of model drugs (salicylic acid, theophylline, and bovine insulin) from the prepared hydrogels ranked as follows: NaOH>lysine>arginine, the sustained-release profile being observed with arginine. The rate of diffusion of the model drug from the hydrogel was inversely proportional to the molecular weight of the cationized neutralizer used. It is concluded that the strategy of neutralization of acidic polymers by basic amino acids has advantage with the respect to both the sustained-release characteristics of the gel and the biocompatibility of the basic amino acids themselves.

Amino Acids↗
PubMed2000

Quantitative evaluation of the bitterness of commercial medicines using a taste sensor.

The bitterness of 11 commercial medicines was evaluated both by a multichannel taste sensor and in human gustatory sensation tests with 15 volunteers. For basic drugs with amino groups in the molecule, such as quinine, there was a comparatively strong relative response electric potential (mV) of channels 1 or 2, those containing negatively charged membranes and the bitterness determined by human gustatory sensation tests. The suppression of the bitterness of quinine by sucrose and aspartame could be quantified using the artificial taste sensor and the results concurred with those from gustatory sensation tests. The usefulness of the sensor was thus confirmed for this type of compound. Anionic drugs, such as diclofenac sodium or salicylic acid gave rise in a negative response electric potential in channels 5 or 6, those containing positively charged membrane, seemed to be useful information even though their tastes are being sour rather than bitter. For drugs with both an amino (cationic) group and carboxylic acid (anionic) group in the molecule, such as theophylline, caffeine, and metronidazole, the relative response electric potential (mV) of channels containing negatively charged membranes was not increased, even though bitterness was observed in human gustatory sensation tests. Therefore, a different design of membrane component is required for more general evaluation of the bitterness of various medicines.

Aspartame↗
PubMed2000

Relationship between p53 gene mutation and protein expression: clinical significance in transitional cell carcinoma of the bladder.

Although the mutated p53 gene has been postulated to induce immunohistochemically-detectable p53 protein, reports regarding the relationship between p53 mutation and p53 protein expression have been contradictory. This study investigated the relationship between p53 mutations and p53 expression and their clinical significance for patients with transitional cell carcinoma of the bladder. Eighty-seven transitional cell carcinoma of the bladder were analyzed by immunohistochemistry (IHC) for p53 nuclear accumulation, and the results compared to mutations detected in the p53 gene evaluated by polymerase chain reaction single-strand conformation polymorphism (SSCP) and DNA sequence analysis. By p53 IHC analysis, positive p53 staining was observed in 50 (57.5%) of the 87 tumors. The specificity of IHC, defined as a percentage of IHC negative (<20%) tumors among tumors without mutation, was 94.6%. Despite the good concordance between p53 mutation and p53 protein expression (p<0.0001), 48.0% (24/50) of the tumors showed p53 overexpression without mutation, and 2 (5.4%) tumors with mutation showed no p53 immunoreactivity. Patients with higher grade (grade 3), stage (stages pT2-4), and p53 mutations had a poorer prognosis by Kaplan-Meier survival analysis. A Cox univariate analysis found that grading (hazard ratio 3.139; p=0.002), staging (hazard ratio 3.832; p=0.0005) and p53 mutation (hazard ratio 2.498; p=0.013) were significant variables in these patients, but no variable was independently associated with an increased survival of bladder carcinoma by multivariate analysis. We found that a 20% cut-off level of p53 overexpression showed the highest correlation with prognosis and p53 mutation, however, p53 overexpression and mutation were not superior to staging as prognostic markers. These data suggest that careful assessment of the TNM staging system remains the most reliable predictive indicator of survival for patients with transitional cell carcinoma of the bladder.

Adult↗
PubMed2000

[Significance of the time course of ST segment elevation just after reperfusion therapy for acute myocardial infarction].

The significance of the time course of ST segment elevation just after reperfusion therapy for acute myocardial infarction was investigated in 25 consecutive patients with acute myocardial infarction and ST elevation. The most elevated ST lead from the standard electrocardiogram on admission was continuously monitored as the ST trend for 72 hr including during the reperfusion procedure. The culprit artery was totally occluded and reperfused without flow delay. Left ventriculograms were obtained after reperfusion and 3-4 weeks later. The most elevated ST level before reperfusion was measured as the maximal level and the ST level 30 min after reperfusion as the reperfused level. The patients were divided into 2 groups, group ST > or = 50% (n = 12) with a decrease of less than 50% of the maximal ST level and group ST < 50% (n = 13) with a decrease of 50% or over 50%. Regional left ventricular wall motion of infarct site, end-diastolic left ventricular volume and ejection fraction were compared between the acute and chronic phase left ventriculograms in each group. In group ST > or = 50%, no significant change was detected in both regional and global ejection fraction, whereas end-diastolic left ventricular volume enlarged significantly in the chronic phase (acute 80 +/- 25 ml/m2 to chronic 95 +/- 17 ml/m2, p < 0.01). In group ST < 50%, regional and global ejection fraction both improved significantly (SD/chord: acute -2.2 +/- 1.5 to chronic -1.4 +/- 0.4, p < 0.001; ejection fraction: acute 50 +/- 14% to chronic 57 +/- 13%, p < 0.01) but end-diastolic left ventricular volume remained the same in the chronic phase. The peak creatine kinase level and the frequency of ST re-elevation at reperfusion were significantly higher in group ST > or = 50% than in group ST < 50% (creatine kinase: group ST > or = 50% 5,496 +/- 2,219 IU/l, group ST < 50% 1,913 +/- 1,180 IU/l, p < 0.0001; ST re-elevation: group ST > or = 50% 83%, group ST < 50% 38%, p < 0.05), although the time from onset of myocardial infarction to reperfusion, the maximal ST level, the degree of collateral development, and the frequency of pre-infarction angina were not different between the 2 groups. Rapid resolution of ST elevation after reperfusion is a useful marker of the improvement of left ventricular function in acute myocardial infarction.

Creatine Kinase↗
PubMed2000

Helicobacter pylori: criminal or innocent bystander?

Most patients with peptic ulcer disease are infected with Helicobacter pylori. However, the infection may not be always causative for the disease. The prevalence of H. pylori infection is about 50% in general. Therefore, half of the patients with peptic ulcer could be infected with this microorganism just by chance. In such cases, H. pylori may do nothing for the ulcer, although it causes chronic active gastritis. This could be the reason for the existence of both H. pylori-positive nonrecurring ulcers and ulcers that recur even after cure of H. pylori infection. H. pylori-positive non-recurring ulcers should be included in non-H. pylori ulcer disease in addition to H. pylori-negative ulcers. NSAIDs are the major cause of H. pylori-negative ulcers, especially H. pylori-negative gastric ulcers. However, more than 10% of ulcers recurred even after cure of H. pylori infection in nonusers of NSAIDs in a 7-year follow-up study. In the same study, 46% of ulcers did not recur in patients in whom eradication of H. pylori failed. There are few (<5%) H. pylori-negative ulcers; about 10% of ulcers recur after cure of H. pylori infection, and about 40% of H. pylori-positive ulcers do not recur. These are all non-H. pylori ulcers, and they represent 30% of all ulcers, which is the general prevalence rate for nonulcer subjects. Therefore, H. pylori may be an innocent bystander in approximately one third of all ulcer patients.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Hemoglobin Pitié-Salpétrière [beta 34 (B16) Val-->Phe] showing erythrocytosis and mild hemolysis in a Japanese man.

We report the first case of Hemoglobin Pitié-Salpétrière (Hb P-S) identified among the Japanese population. The patient was a 33-year-old man referred to us because of severe erythrocytosis and mild hemolysis. DEAE high-performance liquid chromatography showed an abnormal broad peak around Hb A2 peak. Isoelectrofocusing detected abnormal Hb at the position of the Hb F band, and the content of abnormal Hb was estimated at about 25%. An instability test according to the isopropanol precipitation method was positive, and the beta/alpha ratio of biosynthesized globin was slightly reduced. Structural analyses demonstrated the substitution of phenylalanine for valine at beta 34, which was also confirmed by DNA sequencing; that is a single base substitution of GTC-->TTC at codon 34 of beta chain. From these findings, the abnormal Hb was identified as being a high-oxygen-affinity variant, Hb P-S (beta 34 [B16] Val-->Phe). Hb P-S was detected in the patient's mother but not in his father, suggesting that the inheritance pattern is autosomal dominant. It was suggested that the slightly unstable state of Hb P-S caused by the looseness of alpha 1 beta 1 contact could result in mild hemolysis.

Adult↗
PubMed2000

[Comparison of the circadian variation of the time of onset of acute myocardial infarction and of attack of vasospastic angina without significant stenosis].

OBJECTIVES: To study the involvement of vasospasm as the trigger of acute myocardial infarction without significant stenosis, the circadian variation of the time of onset of acute myocardial infarction was compared with that of vasospastic angina without significant stenosis. METHODS: The subjects consisted of 3 groups, 64 patients with acute myocardial infarction without significant stenosis, 101 patients with acute myocardial infarction with one vessel disease and 98 patients with vasospastic angina without significant stenosis. The times of onset of acute myocardial infarction and spontaneous attack of vasospastic angina were recorded and classified according to the 4 periods (0:00-6:00, 6:00-12:00, 12:00-18:00, 18:00-24:00) and the pattern of distribution was compared between the 3 groups. RESULTS: The time distribution of acute myocardial infarction without significant stenosis showed a double peaked pattern at 6:00-12:00 and 18:00-24:00 and was similar to the pattern of acute myocardial infarction with one vessel disease(p = 0.93). Only a single peak in 0:00-6:00 was found in the pattern of distribution of vasospastic angina without significant stenosis and differed significantly from acute myocardial infarction(p < 0.01). CONCLUSIONS: The circadian variation of the time of onset of acute myocardial infarction was similar in patients with or without significant stenosis, and differed significantly from that in patients with vasospastic angina.

Angina Pectoris↗
PubMed2000

[A case of intraoperative pulmonary embolism associated with lupus anticoagulant].

A 51-yr-old woman developed pulmonary embolism while undergoing surgery for breast cancer with Auchincloss method. General anesthesia was maintained with propofol and fentanyl. The course of anesthesia and operation were uneventful until the skin was sutured, when unexplained severe circulatory collapse developed. A widely dissociated EtCO2-PaCO2 suggested pulmonary embolism. The pulmonary circulation was restored 10 minutes after the start of heparin therapy, and the intravenous heparin administration was continued. The patient was extubated uneventfully 24 hours postoperatively. Lung perfusion scintigrams showed defect in right lower lungs (S 6, S 9). Venograms of the lower extremity disclosed thrombosis of the right popliteal vein. Furthermore, lupus anticoagulant was noted in the serum. Patients with antiphospholipid syndrome often develop pulmonary complications including pulmonary embolism and pulmonary hypertension. Intra-operative pulmonary embolism associated with lupus anticoagulant is a rare case.

Anesthesia, General↗
PubMed2000

[Production and clinical application of fibrin sealant with high concentrated fibrin (fibrin patch)].

OBJECT: The sealing properties of fibrin sealant with high concentrated fibrin (fibrin patch) were examined. MATERIAL AND METHODS: A commercial fibrin sealant (Bolheal) produced from pooled human plasma was utilized for this study. The fibrin sealant made of fibrinogen and thrombin solutions mixed in a volume ratio 5:1 was applied as the fibrin sealant with high concentrated fibrin (fibrin patch). The burst pressure of the fibrin clots of either 1:1 or 5:1 mixing ratio, which sealed the small holes, was measured by a water-leak preventing model. The tensile strength of the fibrin patch was measured by the breaking pressure of the fibrin clot. The burst pressure of the fibrin patch, which sealed the dural defect with a diameter of 15 mm, was compared with that of expanded polytetrafluoroethylene (ePTFE). RESULTS: The burst pressure was elevated from 287 +/- 23.1 to 445 +/- 30.5 mmHg by changing the mixing ratio from 1:1 to 5:1. The breaking pressure of the fibrin patch showed 131 +/- 25.4 mmHg and that of the patch mixed at the ratio of 1:1 showed 46.6 +/- 9.9 mmHg. The result of dural repair with the fibrin patch revealed higher sealing effectiveness than that of ePTFE. The burst pressure averaged 70.5 +/- 21.4 mmHg in the fibrin patch samples and 51.4 +/- 13 mmHg in the ePTFE samples. CONCLUSION: The fibrin patch revealed higher performance as a sealant and has the potential to be a candidate for acceptance as the new dural repair material.

Brain↗
PubMed2000

[The effect of suplatast tosilate on immunological parameters for the patients with atopic dermatitis].

A dose of 300 mg/day of suplatast tosilate was administered to one hundred one cases of atopic dermatitis for eight weeks, and the severity scores, peripheral blood eosinophil count, total serum IgE levels, plasma eosinophil cationic protein (ECP) levels, and other immunological parameters before and after the trial were observed and comparatively examined. The results are as follows: 1) Temporary improvements were found in the scores of severity and itchiness on all evaluated skin regions (face, limbs, and trunk). These scores decreased significantly for all observation periods at two, four, six and eight weeks after administration of suplatast tosilate compared with those before the administration (p < 0.01). 2) There was no sign of adverse effects on the drug. In the blood tests, one patient displayed elevated levels of GPT and another showed elevated total bilirubin. In the urine test (qualitative test), one case with positive urinary protein was observed. 3) Clinical examinations including assessment of the immunologic parameters were conducted at an average of 8.68 +/- 0.36th week. The peripheral blood eosinophil count, the percentage of eosinophil, and plasma ECP levels significantly diminished compared with those before administration, but no significant difference was found in total serum IgE levels and LDH levels. 4) The subjects were divided into two groups, one in which the clinical scores were improved by more than five and another with scores of less than five (including worsening), and the fluctuation of the immunological parameters (values before and after administration of the drug) of the two groups were compared. As a result, a significant difference was observed in the plasma ECP levels (p = 0.02) and peripheral blood eosinophil count (p = 0.091), but no difference was observed in total serum IgE levels and LDH levels. From the above mentioned results, the high efficacy and safety of suplatast tosilate in the treatment of severe atopic dermatitis were confirmed. At the same time, a decrease in the peripheral blood eosinophil count and the serum ECP levels were observed, suggesting the possibility that these values could be used as indices of the severity of atopic dermatitis.

Adult↗
PubMed2000

Immunohistochemical observation of actin filaments in epithelial cells encircling the taste pore cavity of rat fungiform papillae.

Epithelial cells are connected to each other around taste pores in rat fungiform papillae. Cytoskeletal components are responsible for the maintenance of intracellular adhesion, and we investigated the identification and localization of actin filaments around taste pores. On the basis of observations made by immunohistochemical transmission electron microscopy comparing with confocal laser scanning microscopy using actin-lectin double staining, actin filaments were found to be localized, encircling the squeezed taste pore cavity, in epithelial cells a few micrometers below the papilla surface. In addition, these observations suggest that the organization of actin filaments around taste pores might be involved in the constriction of taste pores.

Actin Cytoskeleton↗