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Biomedical subjects

T Taguchi

Publications and source records attributed to T Taguchi.

At least 307 records · Page 17Linked to original sources
PubMed1997

Combined chromosome microdissection and comparative genomic hybridization detect multiple sites of amplification DNA in a human lung carcinoma cell line.

Chromosome microdissection-fluorescence in situ hybridization and comparative genomic hybridization (CGH) were performed in parallel to identify the native location of amplified DNA in a human non-small cell lung cancer (NSCLC) cell line exhibiting a homogeneously staining region (hsr) and double minutes (dmin). The native locations of microdissected DNA from the hsr and dmin were 7p12-13 and 8q24, respectively. Southern analysis revealed coamplification of EGFR (7p12) and MYC (8q24). CGH detected amplification of DNA not only from 7p12-13 and 8q24, but also from 9p24 and 10q22.

Blotting, Southern↗
PubMed1997

The distribution and co-localization of nitric oxide synthase and vasoactive intestinal polypeptide in nerves of the colons with Hirschsprung's disease.

The distribution and co-localization of nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) were examined by means of immunohistochemistry and NADPH diaphorase (NADPH-d) histochemistry in the gut of patients with Hirschsprung's disease. In the normoganglionic segment, many nitrergic nerve cells were localized in Auerbach's plexus and nerve fibres were observed preferentially in the circular muscle. The submucosal nitrergic nerve cells were mainly situated in Schabadasch's plexus with occasional cells demonstrable in Meissner's plexus. NOS and VIP were co-localized in most ganglion cells of Auerbach's plexus. In the oligoganglionic segment, a marked reduction of NOS- and VIP- positive nerve cells and fibres was noticed in both the myenteric and submucosal plexuses, and nitrergic fibres had disappeared in the inner layer of the circular muscle. In the aganglionic segment, NOS and VIP were revealed only in extrinsic nerve fasciculi and rami and co-localized in a few fibres. From these observations, the inner layer of the circular muscle of the oligoganglionic segment and the whole of the muscularis propria of the aganglionic segment were considered to be totally lacking in nitrergic innervation. Nitrergic nerves of the human colon comprise both intrinsic and extrinsic elements and the majority of intrinsic nitrergic nerve cells contain VIP. Very low numbers of extrinsic nitrergic fibres contain VIP.

Child↗
PubMed1997

Failure in learning task and loss of cortical cholingergic fibers in microsphere-embolized rats.

The present study was undertaken to elucidate the pathological changes in learning and memory functions and in the metabolism of cortical cholinergic neurons following microsphere embolism in the rat. Microspheres (48 microm) were injected into the right internal carotid artery of rats. Learning and memory functions were measured 7 or more days after the embolism by active and passive avoidance, and water maze tasks. In the biochemical study, cortical acetylcholine and choline contents, and choline acetyltransferase activity were measured. Cortical acetylcholinesterase-containing fibers were quantitatively estimated in the embolized rat. The active and passive avoidance, and water maze tasks were impaired in the microsphere-embolized rat. In the histochemical study, the density of cortical acetylcholinesterase-containing fibers of the ipsilateral hemisphere of the microsphere-embolized rat was decreased, but cell density was unchanged. Furthermore, microsphere embolism decreased the cortical acetylcholine concentration and choline acetyltransferase activity and increased the choline concentration. The results suggest that microsphere embolism causes severe damage to cortical cholinergic neurons, which may be, at least in part, related to the impairment of learning and memory functions in the sustained brain ischemia.

Acetylcholine↗
PubMed1997

A prospective study on the prognostic significance of urokinase-type plasminogen activator levels in breast cancer tissue.

Urokinase-type plasminogen activator (u-PA), which cleaves plasminogen to yield plasmin, is a serine protease of fibrinolysis and is presumed to play a key role in extracellular proteolysis and facilitate the migration of cancer cells. This study was conducted prospectively to evaluate the prognostic significance of u-PA antigen level in breast cancer tissues. u-PA concentrations in the cytosol of 226 breast cancer tissues were determined prospectively by enzyme-linked immunosorbent assay using cytosol fractions prepared for steroid hormone assay. The median follow-up period of the patients was 60 months. Various prognostic factors were evaluated by univariate analysis or multivariate analysis using the Cox proportional-hazards method. Patients with primary breast cancer containing high levels of u-PA had a significantly shorter disease-free survival than patients with low levels of u-PA antigens. In multivariate analysis, a high level of u-PA was an independent risk factor for disease-free survival, being independent of age, axillary node status, and estrogen receptor status. Among the major prognostic factors, a high u-PA antigen level, lymph node involvement, and a positive estrogen receptor status were the most important for predicting relapse-free survival (P = 0.044, P < 0.0001, P = 0.0039). This first prospective study confirmed the prognostic significance of the u-PA antigen level in association with other major prognostic factors. The results of our present study suggest that u-PA in breast cancer tissue might be involved in breast cancer invasion and metastasis.

Age Factors↗
PubMed1997

Total colonic aganglionosis with or without small bowel involvement: a changing profile.

BACKGROUND/PURPOSE: To identify recent trends in the diagnosis and treatment of total colonic aganglionosis with or without small bowel involvement (TCSA), the authors analyzed the findings in 107 patients who had TCSA seen between 1988 and 1992 at 147 medical institutions throughout Japan and compared the results with those of a previous survey conducted between 1978 and 1982. RESULTS: The estimated incidence of total colonic aganglionosis was 1 in 58,084 live births, the male to female ratio was 1.5:1, and the incidence of associated anomalies was 15%. These findings were all very similar to those of the previous survey. Ten years ago, 83.6% of all patients underwent Martin's procedure. In the recent survey, this rate had fallen to 52.1%, and a right colon patch method has also been developed as a new procedure. A marked decrease in the overall mortality rate from 40.9% to 21.5% was observed. However, a high mortality rate persists in those cases with small bowel involvement (33.3%); most such cases are complicated with enterocolitis. CONCLUSIONS: Although the general features of TCSA were similar to those in the previous survey, a substantial improvement in the treatment results for TCSA has occurred. However, further efforts are still required both to prevent and more effectively to treat enterocolitis, especially in cases involving any aganglionosis extending into small bowel.

Enterocolitis↗
PubMed1997

Energy metabolism during cold ischemia and reperfusion in rat small intestinal transplantation: comparison of jejunal and ileal grafts.

BACKGROUND/PURPOSE: In segmental small intestinal transplantation, the question as to whether the jejunum or ileum is the better graft remains unclear. The authors investigated this question regarding nutrition, blood chemistry, and adaptation. METHODS: The authors compared the jejunum and ileum as the proper portion of segmental graft in rat small intestinal transplantation, regarding energy metabolism both during cold preservation and after reperfusion using high-performance liquid chromatography, as well as histological examination. RESULTS: In a cold preservation study, the concentrations of adenosine triphosphate (ATP) in the jejunum versus ileum at 0, 6, 12, 24, and 48 hours of cold preservation were 1.98 +/- 0.93 versus 1.83 +/- 0.84, 0.79 +/- 0.51 versus 0.55 +/- 0.41, 0.60 +/- 0.41 versus 0.58 +/- 0.45, 0.38 +/- 0.28 versus 0.47 +/- 0.39, and 0.44 +/- 0.26 versus 0.55 +/- 0.29 (micromol/g dry weight), respectively. There were no significant differences between the jejunum and ileum at any times of preservation. Adenosine monophosphate (AMP), adenosine diphosphate (ADP), total adenine nucleotides (TAN), and energy charge (EC) also showed no significant differences between the jejunum and ileum at any times of preservation. In the reperfusion study, the concentrations of ATP in jejunum versus ileum 30 minutes after reperfusion after 6, 12, and 24 hours of cold preservation were 0.68 +/- 0.19 versus 0.50 +/- 0.17, 0.71 +/- 0.51 versus 0.42 +/- 0.14, and 0.93 +/- 0.29 versus 0.75 +/- 0.47 (micromol/g dry weight), respectively. Each value was slightly higher in the jejunum than that in the ileum; however, there were no statistically significant differences. TAN showed the same changes as ATP. No significant differences were found between the jejunum and ileum in either AMP, ADP, or EC. The histological findings both just before and 30 minutes after reperfusion were also compared. However, no evident differences were found between the jejunum and ileum. CONCLUSION: These results thus suggest that no significant differences exist between the jejunum and ileum regarding energy metabolism either during cold preservation or after reperfusion in small intestinal transplantation.

Animals↗
PubMed1997

Advances in the analysis of chromosome alterations in human lung carcinomas.

A review of chromosomal analyses of human lung carcinomas is presented. Karyotypic studies have revealed multiple cytogenetic changes in most small cell lung carcinomas (SCLCs) and non-small cell lung carcinomas (NSCLCs). In SCLCs, losses from 3p, 5q, 13q, and 17p predominate; double minutes associated with amplification of members of the MYC oncogene family may be common late in disease. In NSCLCs, deletions of 3p, 9p, and 17p, +7, i(5)(p10), and i(8)(q10) often are reported. The recurrent deletions encompass sites of tumor suppressor genes commonly inactivated in lung carcinomas, such as CDKN2 (9p21), RB1 (13q14), and TP53 (17p13). Despite technical advances in cell culture, the rate of successful karyotypic analysis of lung carcinomas has remained low. Alternative molecular cytogenetic methods to assess chromosome changes in lung cancer, particularly comparative genomic hybridization (CGH) analysis, are discussed. Initial CGH studies confirm the existence of many of the karyotypic imbalances identified earlier in lung cancer and have revealed several recurrent abnormalities, such as 10q- in SCLC, that had not been recognized previously. The further application of such molecular cytogenetic approaches should enable investigators to define more precisely the spectrum and clinical implications of chromosome alterations in lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1997

Long-lasting enhancement of synaptic activity in dissociated cerebral neurons induced by brief exposure to Mg2+-free conditions.

The long-lasting enhancement of periodic clusters of spontaneous excitatory postsynaptic currents (SEPSCs) was examined in dissociated chick cerebral neurons that had been transiently exposed to Mg2+-free solution for 15 min. Since the enhancement was diminished by blockade of synaptic transmission, it clearly depended on synaptic activities. A specific antagonist of N-methyl-D-aspartate receptors (NMDARs) also inhibited the potentiations. Furthermore, the presence of inhibitors of protein and RNA synthesis in the Mg2+-free solution blocked the potentiation. In the potentiated neurons, the frequency of miniature excitatory postsynaptic currents (mEPSPs) increased. In addition, a diffusible molecule(s) that promoted the potentiation appeared to be involved in this phenomenon, since the conditioned medium of Mg2+-free treated neurons enhanced synaptic activity in other dish.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1997

Changes in cholinergic neurons and failure in learning function after microsphere embolism-induced cerebral ischemia.

Central cholinergic neurons play an important role in learning and memory functions. The present study was undertaken to elucidate the pathological changes in learning function and acetylcholine metabolism of the cerebral cortex and hippocampus, following microsphere embolism in rats. Microspheres (48 microns) were injected into the right internal carotid artery of the rats. Learning function was determined using a passive avoidance task on the seventh day after the embolism. In the biochemical study, acetylcholine and choline contents, and choline acetyltransferase activity were measured in the cerebral cortex and hippocampus. Cortical acetylcholinesterase-containing fibers were quantitatively estimated in the embolized rat. Passive avoidance was impaired in the microsphere-embolized rat. Microsphere embolism decreased the acetylcholine concentration and choline acetyltransferase activity in the cerebral cortex and hippocampus. In the histochemical study, the length of cortical acetylcholinesterase-containing fibers was decreased, but cell density was unchanged in the ipsilateral hemisphere of the microsphere-embolized rat. The results suggest that microsphere embolism induces severe damage to cholinergic neurons, which may be related to the impairment of learning function in the ischemic brain.

Acetylcholine↗
PubMed1997

Proton NMR study of triantennary complex type N-linked glycan chains: assignment of proton chemical shifts of the beta-Man residue in a basic unit of the triantennary glycan chain having a GlcNAc beta 1-->6 Man alpha 1-->6 Man beta-->sequence.

The chemical shifts of ring protons of the beta-Man residue in a triantennary complex type N-linked glycan chain having a GlcNAc beta 1-->6(GlcNAc beta 1-->2)Man alpha 1-->6 Man beta sequence were unambiguously determined by two-dimensional proton nuclear magnetic resonance (1H-NMR) spectroscopic methods. The chemical shift of H4 (3.84 ppm) of the beta-Man residue was for the first time revealed to be different from those (approximately 3.77 ppm) of biantennary and alternative type of triantennary glycans having a GlcNAc beta 1-->2 Man alpha 1-->6 Man beta sequence, but quite close to that (3.86 ppm) of a pentaantennary glycan containing a GlcNAc beta 1-->6 residue on the Man alpha 1-->6 Man beta sequence. Thus, the addition of GlcNAc beta 1-->6 residue on the Man-4' residue, whose formation is catalyzed by GlcNAc transferase V, is considered to cause a down-field shift of beta-Man H4 in the complex-type N-glycan chains. One possible explanation of this phenomenon is that the conformation of Man alpha 1-->6 arm is folded back toward the proximal core region, as is the case with the complex-type N-glycan chains with the bisecting GlcNAc residue.

Acetylglucosamine↗
PubMed1997

Occurrence of terminal alpha 2-->8-linked disialylated poly-N-acetyllactosamine chains with Le(X) and I antigenic glycotopes in tetraantennary arms of an N-linked glycoprotein isolated from rainbow trout ovarian fluid.

The Pronase digestion of a 54K glycoprotein present in ovarian fluid of rainbow trout yielded a major glycopeptide. Carbohydrate compositional analysis revealed that this glycopeptide was likely to possess a single large N-glycan chain having low molecular weight oligomers of N-acetylneuraminic acid (oligoNeu5Ac). Structural studies of this glycopeptide revealed novel alpha 2-->8-linked disialylated poly-N-acetyllactosamine chains with Le(X) and I antigenic determinants on the N-linked tetraantennary core glycan. In our recent studies (Kitazume,S., Kitajima,K., Inoue,S., Inoue,Y. and Troy,F.A. (1994) J. Biol. Chem. 269, 10330-10340) we presented evidence that synthesis of alpha 2-->8-linked polysialic acid (polySia) chains is a two-step process in which chain initiation is catalyzed by an alpha 2-->8-sialyltransferase (alpha 2-->8-ST; initiase) that catalyzes synthesis of the first Sia alpha 2-->8-linkage, forming the disialic acid (diSia) unit, Sia alpha 2-->8-Sia alpha 2-->6-Gal-. Chain polymerization is then postulated to be catalyzed by a second enzyme, an alpha 2-->8-polyST ("polymerase") that converts the diSia units to polySia chains. The present structural studies leading to the discovery of alpha 2-->8-linked disialylated units that terminate poly-N-acetyllactosamine chains in an N-linked glycoprotein is further evidence in support of our hypothesis that more than one sialyltransferase activity is required for polySia chain synthesis and polymerization.

Animals↗
PubMed1997

Plasmapheresis in the treatment of rapidly progressive glomerulonephritis.

The present study was carried out to examine the efficacy of plasma exchange in patients with rapidly progressive glomerulonephritis (RPGN). Seventeen patients with RPGN were treated with plasmapheresis as adjunct to immunosuppressive therapy. Of these, 4 had antiglomerular basement membrane (GBM) antibody-mediated glomerulonephritis (GN), 8 had immune-complex GN (5 SLE, 2 HSP, 1 cryoblobulinemia), 5 had pauci-immune GN (3 peripheral antineutrophil cytoplasmic antibody [P-ANCA], 1 cytoplasmic antineutrophil cytoplasmic antibody [C-ANCA], 1 other). Treatment of 10 of these patients with plasmapheresis within the first month of disease onset resulted in a stable renal function for a period extending from 1 to 3 years, except in 2 patients who had high baseline levels of serum creatinine. In the remaining patients, 2 were treated with hemodialysis 6 years later at the end of follow-up. We conclude that plasmapheresis, when used in combination with immunosuppressive drugs, is beneficial, leading to improved renal function.

Basement Membrane↗
PubMed1997

Identification of type VI collagen synthesizing cells in human diabetic glomerulosclerosis using renal biopsy sections.

Although the role of extracellular matrices in the development of glomerulosclerosis has been discussed widely, the cellular origin of type VI collagen in diabetic nephropathy (DN) has remained relatively unexplored. This study reports the distribution and cellular origin of type VI collagen in DN. Type VI collagen-specific oligonucleotide probes and monoclonal antibody were used to assess the relative expression of mRNA for alpha 1 (VI) chain and its translated protein in paraffin-embedded renal biopsy sections of DN. By immunohistochemistry, compared to the control, increased deposition of type VI collagen was noted in the diffuse and nodular lesions of diabetic glomeruli. For cellular localization of type VI collagen mRNA, paraffin-embedded renal sections of the control and DN were hybridized in situ with digoxigenin (Dig)-labeled antisense oligo-DNA probe complementary to a part of alpha 1 (VI) mRNA. In comparison to the control kidney sections, increased numbers of intraglomerular cells (both mesangial and epithelial cells) were positive for alpha 1 (VI) mRNA in renal biopsy sections of DN. From the results, we conclude that overexpression of type VI collagen by intraglomerular cells with its increased deposition might significantly contribute to the glomerulosclerosis found in DN.

Biopsy↗
PubMed1997

Clinical application of biochemical modulation in cancer chemotherapy: biochemical modulation for 5-FU.

The addition of Uracil to Tegafur, a prodrug of 5-fluorouracil (5-FU), has been shown to enhance the antineoplastic effect of 5-FU while reducing the side effects attributed to 5-FU catabolism. Studies of 5-FU levels have shown that the 5-FU concentration in the tumor tissues of patients with head and neck cancer was 16.9 times greater than that in serum and approximately 2-6 times greater than in normal tissue. Similar observations have been made in tumor tissues of patients with breast cancer. The clinical efficacy of UFT, the combination of Uracil and Tegafur in a molar ratio of 4:1, has been studied in a variety of tumor types. An overall response rate of about 23% was obtained, with responses exceeding 30% in patients with head and neck, breast, and bladder cancer. Side effects are predominantly that of gastrointestinal toxicity. Hematologic toxicity is minimal and hepatotoxicity is rare. The UFT combination produces a good clinical effect in a variety of tumor types and is well tolerated.

Adolescent↗
PubMed1997

Negative charges bound to collagen fibrils in the rabbit articular cartilage: a light and electron microscopic study using cationic colloidal iron.

Negative charged sites in the normal rabbit articular cartilage were investigated using cationic colloidal iron methods. In light microscopy of the cartilage stained with the colloidal iron at pH 1.5, a distinct Prussian blue reaction was observed in the pericellular matrix, and a weak blue reaction in the territorial and interterritorial matrices. At pH 7.0, a diffuse Prussian blue reaction was observed in the pericellular and interterritorial matrices. Digestion with chondroitinase ABC, hyaluronidase and keratanase could not erase the Prussian blue reaction. However, the sections digested with collagenase followed by chondroitinase ABC showed significant elimination of the Prussian blue reaction. Electron microscopy of ultrathin sections stained with the colloidal iron at pH 1.5 revealed that the cationic colloid particles were deposited abundantly in the pericellular matrix and dotted along collagen fibrils in the territorial and interterritorial matrices. The present results suggest that negatively charged sites in the articular cartilage derive mostly from chondroitin sulfate, whose proteoglycans firmly bind to collagen fibrils. Such an ultrastructure may maintain the electrostatic microenvironment in the collagen plexus, holding much water in the cartilage matrix, and also producing biomechanical properties such as tensile strength and elasticity of the cartilage.

Animals↗
PubMed1997

Severe chest pain due to gastric anisakiasis.

We treated two cases of gastric anisakiasis presenting with severe chest pain. In both cases, there was a history of prior ingestion of raw saltwater fish. After endoscopic removal of larvae, the chest pain disappeared and never recurred. Other diseases causing chest pain were ruled out by symptoms, signs, blood tests, electrocardiography, chest radiograph, and ultrasonic examination of the heart and abdomen. Thus the chest pain was considered to be caused by gastric anisakiasis. Gastric anisakiasis should be included in the differential diagnosis of acute chest pain.

Adult↗
PubMed1997

Myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis with membranous nephropathy in remission.

A 47-year-old woman developed pulmonary hemorrhage and an increase in proteinuria during remission of membranous nephropathy. Renal biopsy revealed crescentic glomerulonephritis. She also had a high perinuclear antineutrophil cytoplasmic antibody level, so a diagnosis of myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis was made. After immunosuppressive therapy was started, the pulmonary hemorrhage resolved and her proteinuria decreased. Renal biopsy was repeated after treatment and showed histological improvement. This case suggests that there may be a relationship between membranous nephropathy and myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis.

Anti-Glomerular Basement Membrane Disease↗