Biomedical subjects

Y Taniguchi

Publications and source records attributed to Y Taniguchi.

At least 343 records · Page 19Linked to original sources

PubMed1994

Regulated expression of an osteonectin variant in bovine aortic endothelial cells.

Using a mouse SPARC (Secreted Protein, Acidic and Rich in Cysteine) cDNA clone as the probe, three clones were isolated from a cDNA library of bovine aortic endothelial cells (BAEC). Inserted sequences in them were identical with that of bovine bone osteonectin except for the deletion of the TGC codon encoding Cys-193. Northern blot analysis and metabolic radio-labeling of BAEC showed that gene expression and synthesis of the osteonectin variant is stimulated by transforming growth factor (TGF) beta, a basic fibroblast growth factor (FGF), or a naturally occurring splicing variant of hepatocyte growth factor (varHGF).

Animals↗

PubMed1994

Inter-laboratory validation study of the Skin2 Dermal Model ZK1100 and MTT cytotoxicity assay kits.

An inter-laboratory validation study was conducted to evaluate the potential of 4 chemicals to cause irritation with utilizing the Skin2 Dermal Model ZK1100 kit developed by Advanced Tissue Sciences, Inc. (formerly Marrow-Tech, Inc., La Jolla, California, USA). The chemicals tested were sodium dodecyl sulfate (SDS), 1-n-hexadecyl-pyridinium chloride monohydrate (CC), ethanol (EtOH), and dimethyl sulfoxide (DMSO). Eleven Japanese institutions participated in this validation research to evaluate the usefulness of the Skin2 Model ZK1100 kit in accordance with an identical protocol. None of the participating laboratories had previously used the Skin2 Model ZK1100 kit. The MTT-50 value obtained in the individual institutions was 42 to 91 micrograms/ml for SDS, 2.7 to 8.6 micrograms/ml for CC, 2.0 to 9.3% for EtOH, and 11.5 to 21.9% for DMSO. Reproducibility was reasonably good as noted when one test chemical was repetitively tested by the same investigator. MTT-50 values obtained with the present method correlated with DS20 values obtained with Draize's method (r = 0.9881) in one of the participant institutions. The irritation study using the Skin2 Model ZK1100 kit was easy to perform and generated quantitative data. When the test was repeated, reproducibility was demonstrated with a variation of less than 2 sigma. These data suggested that this newly developed in vitro method would be useful in toxicity screening studies in terms of both time and cost, and would serve as a useful alternative to the conventional methods of the eye irritation study.

Animals↗

PubMed1994

Site-specific formation of thyrotropin-releasing hormone-induced gastric ulcers through the vagal system.

The left and right dorsal motor nuclei (DMN) separately innervate the anterior and posterior gastric walls through the left and right gastric branches of the vagus nerve (GBVN) in rats. The present study was carried out to investigate the effects of selective centrally originated excitation of the unilateral vagal system on the gastric area in which vagus-induced gastric ulcers developed. Since intracisternally injected thyrotropin-releasing hormone (TRH) stimulates neurons in the bilateral DMNs to produce gastric ulcers, selective stimulation of the unilateral vagal system was produced by contralateral gastric branch vagotomy before intracisternal injection of TRH. Intracisternal injection of TRH (2 micrograms/rat) into left gastric branch-vagotomized rats resulted in lesion formation only on the posterior gastric wall and not on the anterior wall. In contrast, in right gastric branch-vagotomized rats TRH-induced gastric lesions were observed only on the anterior gastric wall and not on the posterior wall. These results suggest that selective stimulation of the left or right DMN induces site-specific ulcer formation through the left or right GBVN. Next, gastric acid secretion was determined in pylorus-ligated rats to examine a role of acid hypersecretion in site-specific ulcer formation caused by TRH. Of interest was that gastric acid secretion in unilaterally vagotomized rats given TRH intracisternally was significantly smaller than that in sham-operated rats given intracisternal saline, although the former rats developed gastric ulcers, whereas the latter did not. It is therefore speculated that gastric hyperacidity plays a less important role in the peripheral mechanisms of TRH-induced site-specific gastric ulceration.

Animals↗

PubMed1994

Morphological aspects of the cytotoxic action of Helicobacter pylori.

OBJECTIVE: To morphologically investigate the cytotoxic action of Helicobacter pylori on gastric mucosal cells. METHODS: Twenty biopsy specimens were obtained from the antrum and greater curvature of the upper body of the stomach, and examined by electron microscopy to elucidate the process of mucus cell injury induced by H. pylori. RESULTS: Only H. pylori colonies in intimate contact with the mucosal cells caused various cell alterations, including loss of microvilli, mucus depletion, cell membrane injury and degeneration of the cytoplasm. In contrast, H. pylori that were not in contact with the mucosa had no effect on the surface mucus cells. CONCLUSIONS: The results of this study suggested the following mechanism of H. pylori-induced gastric mucosal injury. Intimate contact between H. pylori and the epithelial cell is necessary for cytotoxic action. During the process of cytotoxic action, degradation of the mucous gel layer and the glycocalyx are first caused by the proteolytic enzymes produced by H. pylori. Then the microorganism approaches the surface mucus cell, making intimate contact with the cell surface. Finally, H. pylori adheres directly to the cell membrane, effecting direct action of the toxins on the cell membrane. Subsequently, the degenerative changes induced destroy the cell membrane, resulting in degeneration of the cell itself.

Bacterial Adhesion↗

PubMed1994

Nucleotide sequence of a human genomic DNA fragment containing the PCNA pseudogene and its localization on chromosome 4.

A one kb human genomic DNA fragment, containing a processed pseudogene of a proliferating cell nuclear antigen (PCNA/DNA polymerase delta auxiliary protein), was isolated and sequenced. The PCNA pseudogene consisted of the 3' half of exon 4 and the 5' half of exon 5 of the PCNA gene, and shared 84% nucleotide homology with the human PCNA cDNA. The PCNA pseudogene was localized on human chromosome 4, based on data obtained from a panel of human-mouse hybrid cell lines.

Animals↗

PubMed1994

Relationship between Helicobacter pylori and atrophic gastritis.

OBJECTIVES: To investigate the relationship between Helicobacter pylori and atrophic gastritis. DESIGN AND METHODS: The extent of atrophic gastritis was assessed endoscopically in 97 non-ulcer patients, and their H. pylori status was assessed by enzyme-linked immunosorbent assay. RESULTS: The prevalence of H. pylori infection was greatest in the early stages of atrophic gastritis. Small numbers of H. pylori-negative patients were identified at different stages during the extension of atrophic gastritis. CONCLUSIONS: H. pylori infection precedes the extension of atrophic gastritis, and a minority of patients with atrophic gastritis may never have been infected with H. pylori.

Adolescent↗

PubMed1994

[Assessment of left ventricular count increase with ECG-gated 99mTc-MIBI SPECT using a single-head rotating gamma-camera].

ECG-gated 99mTc-MIBI SPECT was performed in 33 patients, including 17 normal subjects and 16 patients with old myocardial infarction. To compare the findings by echocardiography (UCG), regional wall motion was qualitatively assessed by cine-mode display and quantitatively measured as an increase in regional count from end-diastole to end-systole. The percent count increase and relative count increase was measured to display on the Bull's eye polar map. In the study of normal subjects, the count increase was greater in apical regions and smaller in septal regions. Regional wall motion by this method correlated well with UCG findings (agreement: 97%, complete agreement: 60%). A mild but significant correlation was observed between the count increase by this method and the percent wall thickening by UCG. We conclude that regional wall motion can be accurately evaluated with ECG-gated 99mTc-MIBI SPECT, which thus permits simultaneous assessment of regional wall motion and myocardial perfusion.

Aged↗

PubMed1994

Some personal comments on the Sydney system for the classification of chronic gastritis.

The Sydney system for the classification of chronic gastritis is a system for describing the histopathological findings of a biopsy specimen. It involves the analysis of two to four biopsies of the gastric mucosa taken from arbitrary sites, which, taken alone, are insufficient for extrapolation to the diagnosis of the whole stomach. The system seems to be useful as a computer-oriented method fo documenting the histopathological analysis of the two to four biopsy specimens obtained from the arbitrary sites in the antrum or corpus. One biopsy specimen is obtained from the anterior wall of the antrum, the other from the posterior wall. They would be better obtained from the lesser and greater curvatures, which areas would provide more accurate data concerning the antrum or body. While this may be invaluable for researchers with particular interests, it is quite valueless for the majority of clinicians who must diagnose and treat their patients. When a classification is made, its purposes should, firstly, be clear and definite. Secondly, the classification should be simple and easy to use. If a classification is effective, it will be widely used. However, in this field, it is almost impossible to achieve a classification that will fully satisfy all practitioners and researchers with different interests. The Sydney system alone is not sufficient for the classification of chronic gastritis. It is merely a system for describing the histopathological findings of biopsy specimens. It does not allow for an integrated diagnosis of chronic gastritis of the entire stomach.

Adolescent↗

PubMed1994

A reliable method of embedding a small amount of dispersed cells for electron microscopy.

To embed a small amount of dispersed cells for electron microscopy, we used the supernatant of agarose solution which had been centrifuged beforehand. We also warmed the chamber of the centrifuge by placing a flexible ribbon heater at the bottom of the chamber to prevent the premature gelation of agarose. By these methods, as few as 10(6) dispersed cells can be reproducibly processed and embedded for electron microscopy.

Cells, Cultured↗

PubMed1994

An immunohistochemical study of extracellular matrix components and integrins in human glomerular diseases.

The localization of extracellular matrix components and their cell surface receptors (integrins) was studied in 130 subjects in order to clarify their participation in the progression and aggravation of various types of nephritis. Included in the study were 2 normal subjects, 14 patients with minimal change disease, 2 patients with minimal change nephrotic syndrome, 65 patients with IgA nephropathy, 18 patients with mesangial proliferative glomerulonephritis, 15 patients with membranous glomerulonephritis, 5 patients with membranoproliferative glomerulonephritis and 9 patients with systemic lupus erythematosus (SLE). The distribution of fibronectin (FN), vitronectin (VN), laminin (LN), heparan sulfate proteoglycan (HSPG), type III, IV, V, VI collagen, fibronectin receptor (FNR) and vitronectin receptor (VNR) in the glomerulus was studied employing the indirect immunoperoxidase method. FN, LN, type IV, V and VI collagen, FNR and VNR were found to be distributed in the expanded mesangial region in IgA nephropathy, mesangial proliferative glomerulonephritis and membranoproliferative glomerulonephritis. Deposition of VN was observed in some of the patients. In membranous glomerulonephritis and membranoproliferative glomerulonephritis, the distribution of FN, LN, type IV collagen, FNR and VNR was increased in the thickened loop wall and VN deposition was also observed. Quantitative and functional changes in the extracellular matrix and integrins, therefore, appear to participate in the progression and aggravation of glomerulonephritis.

Adolescent↗

PubMed1994

[Respiratory and circulatory changes under high intra-abdominal pressure].

In order to determine the safety limit of abdominal pressure, the influence of abdominal pressure on the respiratory and circulatory systems was examined by changing it from 0 to 50 mmHg in dogs with carbon dioxide insufflation. Total peripheral resistance increased slightly after pneumoperitoneum but increased rapidly when 30 mmHg was exceeded. Cardiac output tended to decrease with an abdominal pressure above 30 mmHg. Static compliance decreased in response to the abdominal pressure up to 20 mmHg but the decrease became rather gentle when 30 mmHg was exceeded. Peak inspiratory airway pressure increased in response to the increased abdominal pressure up to 30 mmHg followed by small fluctuations thereafter. These evidences indicate that an abdominal pressure below 15 mmHg is desirable for performing a peritoneoscopic operation safely because the biocompensatory system may be impaired when the pressure exceeds 30 mmHg.

Abdomen↗

PubMed1994

[Protracted (lasting) presence of Japanese cedar pollen allergen (Cry j I) in house dust].

We investigated the relationship between the amounts of Cry j I in house dust and airborne Cryptomeria japonica pollen in the same location. Cry j I was still detected in house dust collected two weeks after airborne C. japonica pollen had disappeared. Disappearance of Cry j I in house dust coincided with the disappearance of symptoms in the C. japonica pollinosis patients who lived in the same area. Airborne Cupressaceae pollen appeared during the latter half of the C. japonica pollen season. Disappearance of Cupressaceae pollen did not coincided with the disappearance of the symptoms in C. japonica pollinosis patients. Therefore, some symptoms of C. japonica pollinosis patients after C. japonica pollen disappeared from the air may be caused by pollen which had attached to clothes and been brought indoors.

Air Pollution, Indoor↗

PubMed1994

[Detection of myocardial viability by delayed imaging after 201Tl reinjection].

Recent studies have demonstrated that some underestimation of myocardial viability remained to be not resolved even using reinjection method. So we devised a new technique of reinjection and reimaging, and using this we studied the detectability of myocardial viability in 32 patients of CAD. Exercise imaging (EX) was acquired after initial injection of thallium (111 MBq). Three hours after EX, the second dose thallium (37 MBq) was reinjected, and then the first reinjection image (Re1) was performed. Furthermore, the second reinjection image (Re2) was obtained at 3 hours after the second dose reinjection. SPECT images were divided in basal, mid and apical parts, and totally 13 segments were analyzed by visual scoring (0: severe, 1:moderate, 2:mild hypoperfusion and 3:normal). Twenty-seven (13.4%) of 202 segments of low score (0 to 2) shown in EX were improved in Re2, compared with Re1. Twenty-one (42.0%) of 50 segments of score 0 or 1 shown in Re1 were improved in Re2. These results showed that our devised new method of reimaging 3 hours after the second dose injection was useful to improve in detectability of myocardial viability.

Aged↗

PubMed1994

[Evaluation of myocardial perfusion and ventricular shape in hypertrophic cardiomyopathy using 99mTc-tetrofosmin scintigraphy: comparison with 201Tl myocardial scintigraphy].

Hypertrophic cardiomyopathy (HCM) is known to have the impairment of myocardial perfusion as well as irregularly hypertrophic myocardium. To evaluate myocardial perfusion and ventricular shape in HCM, 99mTc-Tetrofosmin scintigraphy was performed after exercise (Ex) and at resting state (Re) in 10 patients with HCM and was compared with early image (Ea) and delayed image (De) of 201Tl scintigraphy performed after exercise. SPECT images of both 99mTc-Tetrofosmin and 201Tl scintigraphy were analyzed with five scaled visual scores set in 18 segments. The complete concordance ratio between 99mTc-Tetrofosmin (Ex and Re) and 201Tl (Ea and De) images in segmental analysis was 75%. Image quality of 99mTc-Tetrofosmin was seemed to be superior to that of 201Tl scintigraphy. In 9 patients with HCM, 99mTc-Tetrofosmin scintigraphy was performed under the ECG gating and the thickness of septal and free wall was measured. Good correlation was observed with the data by ultrasound cardiography (r = 0.79, p < 0.002 in wall thickness, r = 0.84, p < 0.01 in the ratio of septal wall thickness to free wall thickness). Left ventricular shape (ventricular long axis) was closely resemble to that of left ventriculography by contrast medium. In conclusion, 99mTc-Tetrofosmin scintigraphy is useful for the evaluation of myocardial morphology as well as perfusion abnormality.

Adult↗

PubMed1994

[Enzyme-linked immunosorbent assay for the quantification of Cry j I and Cry j II].

Enzyme-linked immunosorbent assays (ELISA) were developed to specifically quantify the two major allergens from Japanese cedar pollen, Cry j I and Cry j II. Polystyrene microplates coated with antibodies specific for Cry j I or Cry j II were incubated with an allergen and then with biotinylated anti-Cry j I or Cry j II antibody. The bound allergen-biotin Ab complexes were detected with HRPO-conjugated streptavidin and an enzyme substrate. The working ranges of Cry j I ELISA and Cry j II ELISA were 0.3-20 ng/ml and 0.6-20 ng/ml, respectively. Intra- and inter-assay coefficients of variation for reproducibility were 1.5-10.3% and 0.9-12.9%. These ELISA systems showed no cross-reactivity between Cry j I and Cry j II and showed little cross-reactivity with pollen allergens of plants botanically related to the Japanese cedar. Using the Cry j I ELISA and the Cry j II ELISA, it was possible to quantify Cry j I and Cry j II easily and accurately. These ELISA systems will be useful in various fields, especially for the analysis and standardization of the allergens necessary for diagnosis and treatment of Japanese cedar pollinosis.

Allergens↗

PubMed1993

Structure of the canine pancreatic colipase gene includes two protein-binding sites in the promoter region.

Characterization of a lambda phage genomic clone, CL5A, which encodes the canine pancreatic colipase gene, revealed the primary structure of 987 nucleotides (nt) of 5'-flanking sequence, 2066 nt defining the primary transcriptional unit, which is organized into three exon sequences, and 130 nt of 3'-flanking sequence. Exon 1 encodes the amino-terminal signal peptide, the propeptide (Val1-Pro-Asp-Pro-Arg), and the hydrophobic lipid-binding region (Gly6-Ile-Ile-Ile) at the amino terminus of the mature coenzyme. Exon 2 encodes carboxylate residues (Glu12 and Glu15) likely to be involved in binding of pancreatic lipase to colipase at the aqueous-lipid interface. Exon 3 encodes the hydrophobic sequence (Leu54-Tyr-Gly-Tyr-Tyr) that is essential for binding the central tightly structured disulfide-bonded region of the coenzyme to lipid. Southern blot analysis was consistent with the presence of a single-copy colipase gene and a potential colipase gene homologue. Among 16 tissues examined by Northern blot analysis, colipase expression was detected only in pancreas. Proteins contained in nuclear extracts prepared from dog pancreas conferred two regions of DNase I protection coincident for both coding and noncoding strands (positions -62 to -44 (CL-I site) and -128 to -106 (CL-II site) in the coding strand). Competition gel mobility shift experiments indicated that protein-DNA interactions that occur at colipase sites I and II are sequence- and protein-specific and unrelated to the PAN-binding sequence described in the 5'-enhancer region of the rat chymotrypsin B gene (Nelson, C., Shen, L.-P., Meister, A., Fodor, E., and Rutter, W. J. (1990) Genes & Dev. 4, 1035-1043). Nuclear extracts from pancreas and brain, but not liver, contain similar CL-I- and CL-II-binding proteins. CL-I and CL-II represent protein-binding elements that may participate as additional promoter regions in regulated expression of the colipase gene. CL-I contains a central homopolymeric d(G) sequence. CL-II shows a GC-rich region on the noncoding strand (5' GGGGGCGTGT 3') that is similar (8/9 match) to the Sp1-binding sequence.

Amino Acid Sequence↗

PubMed1993

Transient gene expression by SV40 promoter characterizes sequential differentiation of embryonal carcinoma F9 cells into primitive and visceral endoderm.

Transient expression of the chloramphenicol acetyltransferase (CAT) gene under the control of simian virus 40 (SV40)y Moloney murine leukemia virus, human T cell leukemia virus, and cytomegalovirus promoters was stimulated by the differentiation of F9 stem cells into primitive endoderm, but repressed again by further differentiation into visceral endoderm. Deletion mutants of the SV40 enhancer showed that a similar set of motifs is critical for CAT expression at all stages of F9 differentiation, but differentiation dependency was observed even in their absence. The stability of transient gene expression under the control of the SV40 promoter was markedly dependent on F9 differentiation. Appreciable expression was detected even in undifferentiated F9 cells immediately after gene transfection, was maximal at 12 h and declined rapidly thereafter. On the other hand, expression in primitive endoderm increased until 72 h. The decline was accelerated again in visceral endoderm. This shift was somewhat specific to the virus promoter since CAT expression in undifferentiated F9 cells under the control of the elongation factor 1 alpha promoter was more stable than for virus promoters tested. Thus, the change in stability of expression is important for differentiation-dependent virus promoter activity.

Animals↗

PubMed1993

The differentiation-dependent inhibition of SV40 early promoter/enhancer activity in 3T3-L1 cells is mediated through promoter and not enhancer sequences.

Using a plasmid bearing chloramphenicol acetyltransferase (CAT) gene controlled by Simian virus 40 (SV40) early promoter/enhancer complex (pA0cat), we analyzed functional enhancer motifs in 3T3-L1 fibroblast and adipocyte cells. Deletion mutant series of pA0 at the enhancer complex showed that gene expression both in fibroblast and adipocyte cells was dependent on a similar set of enhancer motifs. When pA0 was introduced into 3T3-L1 fibroblasts and the cells were induced to differentiate into adipocytes, CAT activity expressed in fibroblasts was suppressed. Experiments with the deletion mutants at the enhancer complex showed that the suppression was not related to any enhancer motif, and CAT activity was observed with a plasmid having only the promoter sequence. When pA0cat was co-transfected with excess of promoter sequence, the suppression in adipocytes was counteracted. This suggested that negative trans-acting factors of the promoter sequence were responsible for the suppression in adipocytes.

3T3 Cells↗