Search PubMed⌕ Search

Biomedical subjects

T Yamaguchi

Publications and source records attributed to T Yamaguchi.

At least 847 records · Page 47Linked to original sources

Role of bilirubin as an antioxidant in an ischemia-reperfusion of rat liver and induction of heme oxygenase.

The anti-oxidative effect of bilirubin was investigated in an ischemia-reperfusion model of rat liver. The rat portal vessel and liver artery were ligated with a vascular clip, and after reperfusion the urine was collected at intervals. The amount of biopyrrins, the oxidative metabolites of bilirubin, in rat urine reached a maximum 4 hours after reperfusion. Biotripyrrin-a and -b which are biopyrrins isolated from human urine were included in urinary bilirubin oxidative metabolites of rats after reperfusion. The hepatic mRNA level of heme oxygenase-1 (HO-1), the rate limiting enzyme of bilirubin biosynthesis, reached a maximum after 4 hours. Furthermore, the hepatic activity of HO began to rise 4 hours after treatment and remained high until 24 hours posttreatment. These findings suggest that bilirubin acts as a physiological antioxidant in vivo in ischemia-reperfusion and that bilirubin biosynthesis is evoked by oxidative stress.

Animals↗

Cortical glucose metabolism in psychiatric wandering patients with vascular dementia.

The cerebral metabolic rate for glucose (CMRglc) in 18 patients with vascular dementia (VD) and 15 age-matched normal subjects was measured with positron emission tomography (PET) and the 18F-fluorodeoxyglucose technique. Nine of the 18 VD patients manifested abnormal wandering behavior with some psychiatric symptoms: they showed relatively spared CMRglc, which was higher than that of nonwandering patients, especially in the bilateral frontal lobes, left parietal lobe, left temporo-parieto-occipital region, left occipital lobe, and cerebellum. The results suggest that psychiatric wandering behavior of patients with VD could be correlated with partial sparing of CMRglc in the regions listed above.

Aged↗

Analysis of numerical aberrations of specific chromosomes by fluorescent in situ hybridization as a diagnostic tool in breast cancer.

BACKGROUND: Biopsy by fine-needle, aspiration has become a routine technique for the diagnosis of a dominant breast mass. In this study, fluorescent in situ, hybridization (FISH) analysis of interphase nuclei allowed the authors to detect genetic aberrations that are difficult to identify by conventional cytology. METHODS: To investigate ways of minimizing misdiagnosis of the cytology of breast tumors, and detecting genetic aberrations preoperatively, the authors performed FISH with specimens obtained by fine-needle aspiration biopsies of 106 primary breast tumors (78 primary breast cancers, 2 phyllodes tumors, and 26 benign breast tumors). Numerical chromosome aberrations were investigated using 3-color FISH performed with (peri)centromere-specific probes for chromosomes 1, 11, and 17. RESULTS: Sufficient materials for FISH analysis were obtained with aspiration biopsy from 98 of the 106 breast tumors (93.4%). None of the benign tumors nor phyllodes tumors showed evidence of aneusomy for any of the 3 chromosomes. However, 71 of the 74 breast cancers (95.9%) for which sufficient material was available demonstrated aneusomy of at least 1 of the 3 chromosomes tested. The FISH analysis also suggested a possible correlation between aneusomy of chromosome 17 and metastasis to regional lymph nodes (chi-square test = 7.78; P < 0.05). CONCLUSIONS: FISH analysis of fine-needle aspiration biopsies can be a practical and useful method for the preoperative diagnosis of breast carcinoma.

Biopsy, Needle↗

Effects of intracellular pH on high pressure-induced hemolysis of anion transport inhibitor-treated erythrocytes.

Effects of anion transport inhibitors such as 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonate on hemolysis of human erythrocytes at 200 MPa were examined by changing intracellular pH (7.2-7.9). These inhibitors suppressed the hemolysis at neutral pH but enhanced it at alkaline pH. However, such an enhancement was suppressed by cross-linking of membrane proteins using diamide. From the near-UV CD spectra of band 3 and the relation between hemolysis and anion transport in intact or trypsin-treated erythrocytes, it was found that such hemolytic properties were characterized by the binding of inhibitors to band 3. In addition, spectrin detachment from the erythrocyte membrane by high pressure was considerably suppressed by DIDS treatment at neutral pH, but not by DIDS labeling at alkaline pH. These results suggest that the interaction of the cytoplasmic domain of band 3 with the cytoskeleton, which is induced by the binding of ligands to the exofacial domain of band 3, is dependent on the intracellular pH, i.e., the linking is tightened at neutral pH but relaxed at alkaline pH.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

The pyramidal cell layer of sector CA 1 shows the lowest hippocampal succinate dehydrogenase activity in normal and postischemic gerbils.

We examined regional differences in the activity of a mitochondrial respiratory enzyme, succinic dehydrogenase (SDH), in the hippocampi of normal and postischemic gerbils, using a quantitative imaging method. Gerbils (n = 21) without ischemia, and gerbils which had experienced 5 min of bilateral common carotid artery occlusion 12 h or 2 days previously, were sacrificed. Coronal sections of the brains were prepared for quantitative imaging of SDH activity and histological examination. In the control gerbils, SDH activity in the pyramidal cell layer of the CA 1 sector (Sommer's sector) was 106.3 +/- 10.3% (mean +/- SD; SDH activity as a percentage of the cerebellar SDH activity), which was lower than in the other subfields of the hippocampus. SDH activity in the oriens layer, stratum radiatum and lacunosum molecular layer of the CA 1 sector was lower than in the corresponding layers of the CA 2 and CA 3 sectors. After transient ischemia, SDH activity remained unchanged in the CA 1 sector. Histologically, selective neuronal necrosis was observed in the pyramidal cell layer of the CA 1 sector 2 days after ischemia. The observed low level of this mitochondrial respiratory enzyme in the pyramidal cell layer of the CA 1 sector should be taken into account as a possible trigger of the selective vulnerability of the region to ischemia.

Animals↗

Early gastric lymphoma: a clinicopathologic study of ten patients, literature review, and comparison with early gastric adenocarcinoma.

BACKGROUND: Improved diagnostic techniques have increased early detection of gastric lymphoma as well as the early detection of adenocarcinoma. However, clinicopathologic features of early gastric lymphoma are presently undefined. METHODS: Clinicopathologic features of 10 patients with early gastric lymphoma were compared with the same features of 180 patients with early gastric adenocarcinoma. In addition, 46 articles were reviewed to evaluate clinicopathologic differences. RESULTS: Early gastric lymphoma was found in 29.2% of the patients who underwent surgery for gastric lymphoma. Early gastric lymphoma was associated with lymph node involvement in 29.9% of the patients, superficial spreading tumors in 48.6%, and multifocal lesions in 40%. These rates are greater than those in patients with adenocarcinomas (P < 0.05%). The survival rate was identical in both groups. Early gastric lymphoma may develop into large, multifocal tumors, accompanied by lymph node involvement. CONCLUSIONS: Surgical treatment with a wide resection of the stomach and extensive lymph node dissection is necessary for early gastric lymphomas.

Adenocarcinoma↗

Epitope of 24G7 anti-bilirubin monoclonal antibody.

We examined an antigenic epitope recognized by an anti-bilirubin monoclonal antibody designated 24G7 (Shimizu, S., Izumi, Y., Yamazaki, M., Shimizu, K., Yamaguchi, T., and Nakajima, H. (1988) Biochim. Biophys. Acta 967, 255-260). The reactivity of bilirubin-IX alpha, its analogues (III alpha, XIII alpha, and mesobilirubin-IX alpha) and related azo compounds, with 24G7 was compared by means of an enzyme-linked immunosorbent assay (ELISA). The order of reactivity was as follows: (a) aniline azopigment > ethyl anthranilate azopigment > sulfanilic acid azopigment, (b) bilirubin-XIII alpha > bilirubin-IX alpha > bilirubin-III alpha, (c) bilirubin-IX alpha = mesobilirubin-IX alpha. These findings indicated that the epitope is present in (a) the dipyrrolic moiety of the endovinyl (correspond to N-21 and N-22 of bilirubin), or exovinyl types (N-23 and N-24); (b) the dipyrrolic moiety of the endovinyl type, which contains (c) a methyl group (C-2) but not a vinyl group (C-3) in the dipyrrolic moiety of endovinyl type. Therefore, we concluded that the epitope was the region containing the oxo group at C-1, the methyl group at C-2, C-(4,5,6,9), and the N-21 and -22 of bilirubin-IX alpha.

Antibodies, Monoclonal↗

Reconstruction of the laryngeal mucosa. A three-dimensional collagen gel matrix culture.

OBJECTIVE: To prepare an in vitro reconstruction of the porcine laryngeal mucosa, for use in cell biological investigations and as a model for the study of laryngeal disease. DESIGN: Using separately obtained epithelial cells and fibroblasts from porcine laryngeal mucosa, we reconstructed the laryngeal mucosa in a three-dimensional collagen gel matrix culture with air-liquid interface. SUBJECTS: Porcine larynges were from 6-month-old pigs obtained from a local abattoir. RESULTS: We successfully reconstructed the laryngeal mucosa in vitro, including epithelium and lamina propria. The epithelial cells showed five to eight cells in thickness and were well differentiated on the reconstructed lamina propria. The differentiation-specific cytokeratin was positive. CONCLUSIONS: To our knowledge, this is the first report of a reconstruction of the laryngeal mucosa in a three-dimensional collagen gel matrix culture. Fibroblasts and air-liquid interface treatment exert a great influence on the proliferation and differentiation of the cultured epithelial cells. This culture system will help to provide an appropriate physiologic environment to study the differentiation and disease of the larynx.

Animals↗

Applicability of monoclonal antibody Fab fragments as a carrier of neocarzinostatin in targeting chemotherapy.

Two types of fragments of MAb A7 were produced to improve the efficacy and safety in targeting chemotherapy with neocarzinostatin. In this study, 125I-labeled F(ab')2 and Fab fragments of MAb A7 and 125I-labeled MAb A7 were injected intravenously into mice with pancreatic carcinoma xenografts, and the accumulation of each antibody in the tumors was compared. A greater amount of the 125I-labeled Fab fragments of MAb A7 localized in the tumor 2 h following the injection than was observed with the other probes. Relatively less 125I-labeled MAb A7 localized in the tumor 2 h following the injection than was observed with the other two probes. Moreover, reaction of rabbit antimouse IgC with the Fc portion, which is the most immunopotent region of the Fab and F(ab')2 fragments of MAb A7 and MAb A7, was determined by ELISA; the weakest reaction was observed with the Fab fragments of MAb A7. These results suggest that the Fab fragments of MAb A7 may be more suitable carriers of an anticancer drug that is inactivated rapidly in the blood, such as NCS, in targeting chemotherapy than either intact MAb A7 or the F(ab')2 fragments of MAb A7.

Animals↗

p53 gene mutation is not directly related to tumoricidal effects of preoperative radiochemohyperthermia therapy for rectal cancers.

BACKGROUND: Several studies have recently demonstrated that apoptosis of cancer cells is triggered by diverse adjuvant cancer therapies and the induction of apoptosis correlates with the sensitivity of the primary tumor to such therapies. METHODS: We investigated the factors modulating adjuvant cancer therapies by examining p53 gene mutations and chromosome 17p allelic losses in 15 rectal cancers treated by a preoperative combined therapy consisting of radiation, intraluminal hyperthermia and 5-fluorouracil suppositories. RESULTS: The point mutations were detected in 7 of 15 (46.7%) tumors by single-stranded conformational polymorphism and direct sequencing. Allelic losses at chromosome 17p were also detected in 7 of 15 (46.7%) tumors by dinucleotide-repeat polymorphisms. There was no correlation between p53 gene abnormalities and the preoperative tumoricidal effect of the therapy. CONCLUSIONS: We conclude that p53 gene abnormalities do not directly increase resistance to the combined adjuvant therapy.

Alleles↗

Thrombotic occlusion of the coronary artery associated with accidental detachment of undeployed Palmaz-Schatz stent.

We describe a case of coronary stenting in which accidental detachment of the Palmaz-Schatz stent induced thrombotic occlusion of the coronary artery. This case suggests that careful consideration of the risk involving coronary occlusion is mandatory on deciding the therapeutic strategy of the cases in which the unexpanded coronary stent cannot be retrieved following successful deployment.

Adult↗

Taurine reduces experimental liver injury after cold ischemic preservation and a period of rewarming prior to reperfusion.

Livers of male Wistar rats (250-300 g) were isolated and flushed with 10 ml of Ringer's solution and 10 ml of UW preservation solution. Then the organs were stored for 24 h at 4 degrees C in UW solution. Livers of Group 1 were rinsed with 10 ml of Ringer's solution and reperfused after hypothermic storage with oxygenated Krebs-Henseleit solution (95% O2; 5% CO2) in a nonrecirculating system at constant pressure (10 mmHg) and 37 degrees C. Livers of Group 2 were incubated for 30 min at 37 degrees C prior to reperfusion, in order to simulate rewarming of the organ upon surgical implantation. Livers of Group 3 were treated like Group 2, but taurine was admixed to the UW solution (1 mM). Livers of Group 1 showed little signs of a preservation/reperfusion injury, with low enzyme activities of the parenchymal ALT and endothelial purine nucleoside phosphorylase (PNP) in the postischemic rinse solution (ALT: 19.9 +/- 12.4; PNP: 3.3 +/- 0.4 U/liter), adequate portal flow values about 3 ml/g/min and high O2 uptake at the end of the experiment (VO2: 3.2 +/- 0.4 ml/100g/min). Livers of Group 2 exhibited nearly tenfold higher enzyme activities in the rinse solution (ALT: 247.0 +/- 94.7*; PNP: 29.5 +/- 17.0* U/l) and disturbed tissue perfusion with significantly reduced flow values of about 2 ml/g/min during the first 10 min of reperfusion. As a result, the recovery of O2 uptake was only 2.2 +/- 0.3 ml/100 g/min*. Addition of taurine (Group 3) resulted in a significant reduction of the enzyme loss (ALT: 96.2 +/- 50.0#; PNP:12.4 +/- 7.0# U/liter) and improved portal flow values and O2 uptake at the end of reperfusion (2.7 +/- 0.3 ml/100 g/min#). The results give evidence for the importance of the rewarming period after hypothermic storage, which is inevitable during implantation of the organ in vivo. Taurine seems to exert a protective effect, affecting both the vascular endothelium and parenchymal tissue (*p < 0.05 vs Group 1; # p < 0.05 vs Group 2).

Adenosine↗

TPN-induced fulminant beriberi: a report on our experience and a review of the literature.

Fulminant beriberi, once considered a rare disease, is now being encountered more frequently, yet little is known about its clinical features. This study was undertaken to determine the clinical features of total parenteral nutrition (TPN)-induced fulminant beriberi by reviewing the clinical data on 10 of our own patients who developed this complication, and 33 cases documented in the literature. TPN-induced fulminant beriberi became evident 4-40 days after the initiation of TPN, and was more likely to develop in patients with malignancies, ulcerative colitis, and short bowel syndrome, as well as in those receiving chemotherapy. Although the patients manifested various symptoms, very few developed the classical signs of beriberi or the constant findings seen in alcoholic patients. The severity of metabolic acidosis was extremely high and refractory to bicarbonate administration, but it responded quickly to intravenous (i.v.) thiamine. Thus, rapid i.v. administration of at least 100 mg of thiamine is imperative, and the patient must be transferred to the intensive care unit when TPN-induced fulminant beriberi develops.

Acidosis↗

Renal cell carcinoma in a patient with Beckwith-Wiedemann syndrome.

We report the case of a patient with Beckwith-Wiedemann syndrome (BWS) who developed renal cell carcinoma (RCC). At birth, this patient presented with macroglossia, diastasis recti, mild gigantism, hepatomegaly and hypoglycemia, and the diagnosis of BWS was made. At 22 months, an intrapelvic rhabdomyosarcoma was detected and resected. At 37 months, computed tomography (CT) demonstrated a small mass with high attenuation in the right kidney, which was surgically confirmed to be RCC.

Beckwith-Wiedemann Syndrome↗

Epitope mapping of capsid proteins VP2 and VP3 of infectious bursal disease virus.

Twenty hybridoma cell lines producing monoclonal antibodies (MAbs) against serotype 1 infectious bursal disease virus (IBDV) of GBF-1 and the attenuated GBF-1E strains were produced. The MAbs recognized major structural proteins VP2 and VP3. MAb recognition sites were mapped using recombinant Escherichia coli clones which expressed N-terminal and (or) C-terminal truncated virus antigens, and competitive-binding assays. At least 3 conformation-dependent serotype 1 specific virus neutralizing antigenic sites and a linear antigenic site were defined on VP2 and VP3, respectively. Two of the conformational virus neutralizing antigenic sites were localized in the central area of VP2 consisting of 156 amino acid residues, and the linear epitope was localized in C-terminal 105 amino acid residues of VP3. Another conformational virus neutralizing antigenic site recognized with the virus neutralizing MAb GK-5 was not defined because GK-5 did not react with virus antigen expressed in recombinant E. coli. The conformational antigenic site was supposed to be composed of tertiary or quaternary protein structure, which may not be constructed in recombinant E. coli.

Animals↗

Fragile bone syndrome associated with craniognathic fibro-osseous lesions and abnormal modeling of the tubular bones: report of two cases and review of the literature.

OBJECTIVE: To report examples of disorders characterized by bone fragility, calvarial and/or gnathic fibro-osseous lesions, and metadiaphyseal undermodeling of the tubular bones. DESIGN: The clinical, radiological, and pathological features of two patients are described and the literature reviewed. PATIENTS: The patients comprised a 10-year-old boy and a 48-year-old woman. The former exhibited multiple fractures starting in early childhood and calvarial masses which developed in late childhood; the latter showed a mandibular mass. RESULTS: Calvarial doughnut lesions, osteopenia with coarse bony trabeculae, and undermodeling of the lower limbs were radiologically demonstrated in the first patient, while multiple sclerotic foci in the maxilla and mandible, spontaneous bowing of the right femur, and minimal undermodeling of the tibiae were demonstrated in the second. Bone biopsy of the iliac crest in the first patient revealed histologically normal bony trabeculae. Bone histomorphometry suggested an increased osteoid surface. Osteoid volume was also slightly increased. The pathological findings of the mass in the jaw in the latter patient were consistent with it being a fibro-osseous lesion. The literature review revealed several patients whose features overlapped with those of our patients. CONCLUSION: These patients may represent a group of fragile bone syndromes which differ from osteogenesis imperfecta.

Bone Diseases, Developmental↗